Premium Gas

[Kaotic Lazagna]

okay, to make this short, i filled up with premium gas at Chevron, the only place i ever get gas...i drove on average of 70 mph...and i just filled up again and calculated my mpg...i got 39 mpg. ????? when i fill up with regular and drive at an average of 65 mph, i get 36-38 mpg. :iono:

but yeah, i'm not sticking with premium, just wanted to test it out.

can anyone tell my why i was able to get better gas mileage with premium? i didn't think it mattered which grade fuel??????

[jamal1984]

someone at the dealership told my not to use 87, they told me rather use 89 or premium. I have no ideas, but i would like to know more about this too.

[daq421]

Manual says regular (87 octane) gas, wallet says regular gas, car get regular gas...

-Peter

[jamal1984]

Manual says regular (87 octane) gas, wallet says regular gas, car get regular gas...

-Peter

hahha same here, my wallet is not enough to fill Premium now a day, beside i filled one time and i heard more noise from the engine, dind't pay attention to MPG.

[absenter]

I remember my Mini Cooper S only took premium. Isn't it called premium for a reason though? Makes sense to me you would get better mpg. I'd fill up with premium all the time if I had the ends.

[static808]

premium gas is typically used in order to prevent a symptom called engine knocking. Engine knock happens when you get preignition of the fuel / air mixture before the spark can light it and give you a clean burn at top dead center of the piston. Essentially the mixture is combusting too early. Higher octane fuel is more resistant to preignition from compression. Thats all. Generally high compression engines require higher octane fuel but thats changed dramatically based on really advanved engine management systems technology. It used to be that anything with more than 9:1 was running premium, but nowadays engines can run 11:1 on 87 octane. just check out some honda engines. How? Well I'm not sure but our Yaris is set up to run on 87 octane without knocking so thats what I use. The reason you can get more power by running 91+ octane is that the engine management computer probably just advances the timing to take advantage of the better fuel. Will it increase fuel economy? Perhaps a tiny bit but certainly not 20% more. There is absolutely no evidence that running higher octane fuel in an engine thats supposed to run on 87 will make any difference. Totally different story for the bigger and badder engines. Higher compression, longer stroke, high revving engines need it. the yaris...not so much. stick with the 87. if the prices in your area are similar to mine, you'll appreciate the savings!

--B

[absenter]

That's what I meant to say...errr :bow:

[Spades]

It is not to prevent engine knock. Engine knock is from rods comming loose or lifters rattling,ect.

The real reason people use higher octane fuel is to prevent a thing called "Predetonation"...I made a whole post on this in another thread on this same forum.

QUOTE:

High octane rating only determines at what point the fuel will combust. A high octane fuel is to prevent a thing called "Predetonation" from occurring.
Predetonation is not a term you ussually hear in parking lots full of kids showing off their cars, ussually it is used at the dragstrip listening to guys talk about their 400+HP 4cyl boosted cars.

Predetonation is what happens when due to pressure in the combustion chamber the fuel ignites prematurely before the spark plug triggers. This is a very bad thing, because if the number 1 cyl predetonates, it goes against the crankshaft being turned by the pistons that are firing in the correct order with their spark plugs.

The force inside a cylinder chamber becomes increasingly higher when you try to force 20 PSI of boost into it. When the piston goes on what is called the compression stroke(the stroke where it mashes the mixture of air and gasoline together in preporation to be ignited) the pressure can sometimes be enough to cause the mixture to explode.

High octane rated fuel is used to prevent the gasoline and air mixture from blowing up before it is supposed to. The only benifit to using high octane fuel on a car that was designed for 87 octane piss water is that it sometimes burns cleaner because some gas stations may put more adatives in it and sometimes it is a slightly better grade of fuel.

If you ever get boosted or change the compression to something radical(say 14 to 1) then look into 89 octane, untill then, feel free to waste your cash on the gas that costs 30 cents more a gallon.

END QUOTE



P.S. You do NOT get more power from running higher octane fuel unless you are running insane compression or boost. It does not burn cleaner, it does not burn hotter. The only thing high octane fuel is cause it to combust later than a lower octane fuel would. Your computer will neither advance NOR retard the timing just by going up 2 points in octane. Better gas mialge is completely coincedental, and is not scientificaly probable.

The only thing high octane fuel in your little 106hp gas miser engine will do is drain your pockets of the excess money you seem to possess. Be prepared for extra fuel injection services...because the delayed ignition doesnt allow for as clean of burn, so your engine will get covered with carbon deposits on the valvetrain.

P.S.P.S. If you dont belive me look on the internet, or look in a issue of sport compact car, they already debunked the whole "octane=hp" bullcrap.

[fu_im_from_texas]

[QUOTE=Kaotic Lazagna]

can anyone tell my why i was able to get better gas mileage with premium?QUOTE]

This post has gotten :offtopic:

I think your mpg fluctuated because of other factors. A change in temp could cause the tire pressure to change by 10% resulting in better/worse mpg. Maybe you did more city driving? More passengers = more weight, less mpg...

Bottom line, you experianced higher mpg on this tank of gas which could be indepandant of the octane rating. mpg is affected by so many factors, you may never know excatly why that tank was slightly better.

back off topic, engine knock and predetonation are two terms for the same thing...

[Kaotic Lazagna]

[QUOTE=Kaotic Lazagna;69757]

can anyone tell my why i was able to get better gas mileage with premium?QUOTE]

This post has gotten :offtopic:

I think your mpg fluctuated because of other factors. A change in temp could cause the tire pressure to change by 10% resulting in better/worse mpg. Maybe you did more city driving? More passengers = more weight, less mpg...

Bottom line, you experianced higher mpg on this tank of gas which could be indepandant of the octane rating. mpg is affected by so many factors, you may never know excatly why that tank was slightly better.

back off topic, engine knock and predetonation are two terms for the same thing...

not sure why either. my factors remaind the same, for the most part. the only difference is that i was driving faster and the gas itself. but i'm not willing to get another tank of premium to find out. lol...:laugh:

[fu_im_from_texas]

not sure why either. my factors remaind the same, for the most part. the only difference is that i was driving faster and the gas itself. but i'm not willing to get another tank of premium to find out. lol...:laugh:

one of my best tanks was 42.xx mpg...from el paso to dfw...700 miles of +80 mph... :iono:

[Spades]

[QUOTE=Kaotic Lazagna]

can anyone tell my why i was able to get better gas mileage with premium?QUOTE]

This post has gotten :offtopic:

I think your mpg fluctuated because of other factors. A change in temp could cause the tire pressure to change by 10% resulting in better/worse mpg. Maybe you did more city driving? More passengers = more weight, less mpg...

Bottom line, you experianced higher mpg on this tank of gas which could be indepandant of the octane rating. mpg is affected by so many factors, you may never know excatly why that tank was slightly better.

back off topic, engine knock and predetonation are two terms for the same thing...


It is on topic...explaining how octane works answers the question. Your better MPG was a result of another factor and is completely seperate from fuels octane.

P.S. the actual term for Predetonation is called "Pinging"...not knocking...a knock normally refers to a rod or valvetrain noise...course...predetonation, bad lifter, rod knock, piston slap...all the same thing, right?

[Black Yaris]

89 octane was tested to get the higher mpg rating posted on the window sticker of our car

[elsteverino889]

Use reg and its cheap

[static808]

[QUOTE=fu_im_from_texas;69779]


P.S. the actual term for Predetonation is called "Pinging"...not knocking...a knock normally refers to a rod or valvetrain noise...course...predetonation, bad lifter, rod knock, piston slap...all the same thing, right?

ooops! i meant engine pinging, you are correct! but many use the terms ping and knock interchangeably. either way, higher octane prevents preignition or predetonation, as we stated, and shouldnt be used in our yarii. kaotic's higher mpg may have been cause by better drafting behind cars, a stronger tailwind, who knows! but it definitely wasnt the use of higher octane gas...and i agree that this is definitely ON TOPIC! now, if i started talking about how kaotic's choice of laundry detergent affected his mpg, that would be considered off topic...

--B

[ChinoCharles]

Screw all of you, I'm going to make the 20 minute drive up to Ravenna and grab some 105 octane. I'll let you know what happens. :wink: :laugh:

[AlphaFox]

89 octane was tested to get the higher mpg rating posted on the window sticker of our car

Where did you read that??

[Kaotic Lazagna]

[QUOTE=Spades;69789]

ooops! i meant engine pinging, you are correct! but many use the terms ping and knock interchangeably. either way, higher octane prevents preignition or predetonation, as we stated, and shouldnt be used in our yarii. kaotic's higher mpg may have been cause by better drafting behind cars, a stronger tailwind, who knows! but it definitely wasnt the use of higher octane gas...and i agree that this is definitely ON TOPIC! now, if i started talking about how kaotic's choice of laundry detergent affected his mpg, that would be considered off topic...

--B

lol...i use Tide for the most part. that was when i was gettin 36-38 mpg. then i switched to All, and i got 39 mpg. :laugh: really tho...this happened...but there better be no connection or else imma go crazy!

[static808]

[QUOTE=static808;69893]

lol...i use Tide for the most part. that was when i was gettin 36-38 mpg. then i switched to All, and i got 39 mpg. :laugh: really tho...this happened...but there better be no connection or else imma go crazy!

hahaha, DAMN! i gotta stop using that costco shit and start getting some brand name laundry detergent! maybe if i use fabric softener, my sienna will get hybrid-like numbers...hmmmm...

--B

[Pavel Olavich]

[QUOTE=Kaotic Lazagna]

can anyone tell my why i was able to get better gas mileage with premium?QUOTE]

This post has gotten :offtopic:

I think your mpg fluctuated because of other factors. A change in temp could cause the tire pressure to change by 10% resulting in better/worse mpg. Maybe you did more city driving? More passengers = more weight, less mpg...

Bottom line, you experianced higher mpg on this tank of gas which could be indepandant of the octane rating. mpg is affected by so many factors, you may never know excatly why that tank was slightly better.

back off topic, engine knock and predetonation are two terms for the same thing...


Your conclusions that you get better gas milage with premium is VERY UNSCIENTIFIC....profoundly subject to massive error. You drive one time, or one tank and you make such silly conclusions? You can drive the same exact route 10 times, and your milage will vary from time to time because you will drive the car differently, too many variables change, temperature outside, number of red/green lights, how fast you drive, etc...don't over simplify this issue so much!

The fact is, your car is engineered for 87 octane, and to use higher will NOT provide better gas milage, and in fact will show LESS milage.

There is this dillusion all over the net that using premium in a car engineered for regular is better. This is an old wive's tale, and urban myth.

Using premium in your Yaris actual can make it have LESS POWER, lower MPG, and run with less pep. Many believe (I do too) that running too high an Octane will shorten the life of your engine because it is not tuned for higher octane, and this could introduce incomplete combustion, and detonation, which stresses the engine and over time will shorten it's life.

Don't fall into this bullshit thinking....your car runs the best with 87 octane, and it gets the best MPG with 87....don't get sucked into this thinking that spending more $$ for premium is good for your car, better for MPG, and makes it more powerful...this is all a myth.

For our Yaris, HIGH octane = lower power, less MPG.

And engine knock and detonation are the same things....nothing to do with rods, old engines, etc....

[marcus]

all you need to know is 87 octane burn faster than premium.. although you are paying more on premium ur actually running more km as well..so overall premium is a way to go.abit cleaner than 87...now going 94 aint worth it unless you adj ur timing..

[Moose]

[QUOTE=fu_im_from_texas;69779]


It is on topic...explaining how octane works answers the question. Your better MPG was a result of another factor and is completely seperate from fuels octane.

P.S. the actual term for Predetonation is called "Pinging"...not knocking...a knock normally refers to a rod or valvetrain noise...course...predetonation, bad lifter, rod knock, piston slap...all the same thing, right?

However, when an incorrect fuel is used- i.e., a car requires 93 octane and you use 87, the vehicle's knock sensor can be heard over time. Our car does have a knock sensor, and if it were activated, you would hear, literally, a knocking- not the engine, but the sensor itself. It is a product of the engine having to adjust timing radically to use a lower octane gasoline. The first time someone radically tunes a Yaris without adjusting the air fuel ratio, they will likely hear a knocking- the knock sensor.

Pinging is heard when there is premature detonation, and also when all fuel is not being burned. Folks that use nitrous or turbo without changing spark plugs
often hear pinging.

Will you hear knocking when using 93 octane in a Yaris? Nope.
Will you hear knocking when using 87 octane in a Lexus ES330? Yup.

[Kaotic Lazagna]

[QUOTE=Kaotic Lazagna;69908]

hahaha, DAMN! i gotta stop using that costco shit and start getting some brand bame laundry detergent! maybe if i use fabric softener, my sienna will get hybrid-like numbers...hmmmm...

--B

oh yeah, i use fabric softener too! it's the one in the clear, navy blue bottle...:laugh:

okay, i'm getting off topic in my own thread. heh.

[Kaotic Lazagna]

[QUOTE=fu_im_from_texas;69779]


Your conclusions that you get better gas milage with premium is VERY UNSCIENTIFIC....profoundly subject to massive error. You drive one time, or one tank and you make such silly conclusions? You can drive the same exact route 10 times, and your milage will vary from time to time because you will drive the car differently, too many variables change, temperature outside, number of red/green lights, how fast you drive, etc...don't over simplify this issue so much!

The fact is, your car is engineered for 87 octane, and to use higher will NOT provide better gas milage, and in fact will show LESS milage.

There is this dillusion all over the net that using premium in a car engineered for regular is better. This is an old wive's tale, and urban myth.

Using premium in your Yaris actual can make it have LESS POWER, lower MPG, and run with less pep. Many believe (I do too) that running too high an Octane will shorten the life of your engine because it is not tuned for higher octane, and this could introduce incomplete combustion, and detonation, which stresses the engine and over time will shorten it's life.

Don't fall into this bullshit thinking....your car runs the best with 87 octane, and it gets the best MPG with 87....don't get sucked into this thinking that spending more $$ for premium is good for your car, better for MPG, and makes it more powerful...this is all a myth.

For our Yaris, HIGH octane = lower power, less MPG.

And engine knock and detonation are the same things....nothing to do with rods, old engines, etc....


i don't believe that premium bullshit one bit. i just decided to run some premium through my tank. and i know it wasn't scientific, but i was merely just telling you guys something. i never said anything about "oh i got so and so mpg with premium, YOU ALL SHOULD START USING PREMIUM!" and i know that variables change with every drive, but i kept all the factors that i can control the same.

and i know that the Yaris was engineered for regular (87) gas. it's a friggin' econo car. who would make an economic car that requires premium gas?

i've seen tests regarding different grades of fuel, and the results were that basically, "if your car will appreciate the higher grade, then it'll get a few more hp".

[Go4th]

Consumer reports ranked Costco brand Kirkland’s "liquid" laundry detergent number 1 and tide number 2.. FYI.

[Kaotic Lazagna]

Screw all of you, I'm going to make the 20 minute drive up to Ravenna and grab some 105 octane. I'll let you know what happens. :wink: :laugh:

are you really going to do this? i wouldn't, but if you have the money...lend me some. hahaha. j/k.

[Kaotic Lazagna]

Consumer reports ranked Costco brand Kirkland’s "liquid" laundry detergent number 1 and tide number 2.. FYI.

hmmm, i forgot to get detergent when i last went there, that's why i had to buy All...next time i go grocery shopping again at Costco.

[Kaotic Lazagna]

all you need to know is 87 octane burn faster than premium.. although you are paying more on premium ur actually running more km as well..so overall premium is a way to go.abit cleaner than 87...now going 94 aint worth it unless you adj ur timing..

i'm still not getting premium because even if it does help increase mpg, which i never thought it did, it's not worth it imo.

we use premium once in a while in our cars, and every time we do, it gets less mpg. in my dad's Camry, it decreased the mpg by 2 or 3. when i had my GTI, it really decreased it. in fact, the best mpg i got with the GTI, i used Safeway gas.

[Spades]

I know brand is off topic, but be carefull filling up at those grocery store chain gas stations. There is a reason their gas is so cheap.

P.S. I agree by all means Moose...low octane in a boosted or high compression car is bad news...I was hoping my post implied that. My whole goal was to get people to understand what octane rating meant.

P.S.P.S. I do not belive that higher octane fuel burns cleaner and has less emissions than 87 does in a 106hp car... the reason is because while the higher octane fuel is normally better quality and may have more addatives, the fact that your little engine is trying to compensate for the delayed ignition ussally means it will be polluting more, and ussually the car without boost or high compression will not be able to burn all the fuel completely since it was ignited a split second later than it should have beem. I have never seen a cars window sticker reccomending what octane to use for best gas milage...wierd.

And Marcus, that is some retarded logic. 87 octane does not "burn faster" than premium, it just ignites slower, the burn process takes the same amount of time, your engine does not speed up or slow down. All premium does in your econbox is ignite slower, leaving more deposits in the engine. The engine will not magically gain more RPM's or torque and all of the sudden move slower or faster based on the octane rating. It is NOT cleaner than 87 octane, even with the added detergants most places put in their 92, your engine isn't meant to run it so it will pollute more.

Oh, and screwing with the timing on a stock car is for honda boys that want to f-ck up their 89 civic.

[spkrman]

I tried the premium thing... it seemed to help most on the top end.. but nothing amazing. MPG seemed to be better when driven harder... but under normal conditions, no difference.

shell 87 for me, seems to be the most consistent gas.

More than octane - WHERE you buy your gas seems to make the biggest difference.

[churp]

I'm just an old toad but.......Higher compression does make more power thus better gas milage. Without computers on our engines 9:1 compression is about tops for 87 octane, the ECU is the only thing keeping the engine from self distruction at 10.5:1 by adjusting the timing because of the detonation sensor feedback. With better octane the timing can be advanced to a much more efficient state thus getting better millage and power.

An example is back in the early seventies gas crisis...one group modified a Pinto to try to improve milage. Through the use of another cam, increasing compression from 9:1 to 12:1, and using water injection to reduce detonation (research water/alcohol injection in combination with turbo/super charging) they increased horsepower 50% and milage went from 30 to 45 on a controlled track. Now 12:1 is pretty extreme but as long as you can control detonation (water injection) you can set your timing to take advantage of this. No ECU's back then, now we do! Now we have the ECU setting our timing through detonation sensors to the optimum setting for efficiency (we maybe could run 87 octane at 10:1 compression but without the real world timing adjustments done by an ECU, performance would be crap).

In other words due to the ECU adjusting timing in real time, YES you should get better gas milage and performance with higher octane fuel !!!!! Does it pay to use premium? If you get 3% gain in milage and premium is 2% more cost than 87 octane go for it because performance increases also. I don't have a scangauge yet, but I'd go by the facts before the myth that higher octane doesn't help. Computers have really changed the word since the 70's.

:headbang:

[churp]

I forgot to add...the Yaris was designed to run on 87 octane for the convenience of the consumer ....that doesn't meen that higher octane isn't better when the computer adjusts for it!!!

[static808]

If you get 3% gain in milage and premium is 2% more cost than 87 octane go for it because performance increases also. :headbang:

this is where the problem lies for many of us: premium gas is usually 7-10% more expensive than regular. and i dont think we'll see a 7-10% in performance or mpg, so from a strictly economical standpoint, its not worth it.

--B

[churp]

:iono: I'll agree it probably isn't for the milage people but for the lead foots...maybe!! I like the idea of the scangauge just to check...maybe after Uncle Sam gets his hand out of my pocket this month I'll be able to afford one.

:burnrubber:

I rethought this and looked at the Minnesota gas (which is all 10%ethanol) prices tonight are $2.59 reg and $2.61 prem. ....so premium is 0.8% more costly than regular-----so 'if' my mpg went from 37 to 37.3 it is worth putting in premium!!!!......I'm going to try the extra 2 cents and won't wait for the scangauge :eyebulge:

[Kaotic Lazagna]

prices tonight are $2.59 reg and $2.61 prem. ....so premium is 0.8% more costly than regular-----so 'if' my mpg went from 37 to 37.3 it is worth putting in premium!!!!......I'm going to try the extra 2 cents and won't wait for the scangauge :eyebulge:

wow. over here, the difference between premium and regular is no less than 20 cents. for example, if gas is $3.18 for regular, premium is no less than $3.38. sometimes, the price difference between regular and plus is 12-15 cents already!:eek:

[churp]

Sorry ....the 2 cent difference was between reg and plus (87--89 octane). Think I can still get Premium in Iowa, 20 miles away otherwise no premium for at least 50 miles here in Minnesota, and then it would only be a few stations at most. The 20 cent difference would require about 2.4 mpg increase from 37mpg to be worth it.. enough said,,,

[Black Yaris]

2.60 reg
2.70 mid
2.80 pre
prices here in Toledo Ohio on my way home today

[Kaotic Lazagna]

Sorry ....the 2 cent difference was between reg and plus (87--89 octane). Think I can still get Premium in Iowa, 20 miles away otherwise no premium for at least 50 miles here in Minnesota, and then it would only be a few stations at most. The 20 cent difference would require about 2.4 mpg increase from 37mpg to be worth it.. enough said,,,

you guys don't have premium there? can't figure out why...but yeah, i don't think and added 2.4 mpg is worth it still since you won't be able to go back to regular just incase premium prices spike.

[Kaotic Lazagna]

2.60 reg
2.70 mid
2.80 pre
prices here in Toledo Ohio on my way home today

oh how i wish gas prices here were that low.

[static808]

chevron. 3.32 regular. 3.51 premium. 'nuff said...

--B

[ChinoCharles]

WOW! I paid $2.64 and I felt outraged. We had gas below $2.50 for a long time recently.

[yrsdrgn]

WOW! I paid $2.64 and I felt outraged. We had gas below $2.50 for a long time recently.

hehe.... our gas is $3.37 :cry: and that's for regular!!!!

[Kaotic Lazagna]

man, Cali has outragous gas prices!

[forpinks]

..... I never touched 87 when I fill up my own cars, even my old AE92...
but to tell you the truth from my experience...

I like the 91-93 octane from Shell or Chevron on the freeway, but 89 I think is the best for city driving... Oh yeah, my tC is running on 87 now and its an
auto-mall brand... I'll try 89 then 91 when the meter hits near "Empty", its tank is still full and I haven't drove it far yet, only about 80miles and I got it when it has only 2 miles... then I'll tell you the difference!

[barryware]

one of my best tanks was 42.xx mpg...from el paso to dfw...700 miles of +80 mph... :iono:


My mileage goes to crap at 80+. I get the best at 70 or so. 37-38 mpg is the best I have ever gotten.

[marcus]

ok i got to add sumthing here.. first of all i been thru a few cars and going to premium give you not just 3% increase on mileage.. you get a lot more. id say close to 10% and thats measured on a cavalier..which i borrowed for 2 weeks and my celica as well which i had for 6 years..and using premium is cleaner than regular gas..now going to 92 or 94 octane which i have tried as well.. not much difference on mileage compare to premium but then again going higher octane really requires adj ur timing to about 10 -15 degree adv. then ull have better take off..and the rules of engagement is adj ment need the feel as well.. makes sure ur engine is not knockin' other wise ur too advance. retard bit by bit..

[Pavel Olavich]

ok i got to add sumthing here.. first of all i been thru a few cars and going to premium give you not just 3% increase on mileage.. you get a lot more. id say close to 10% and thats measured on a cavalier..which i borrowed for 2 weeks and my celica as well which i had for 6 years..and using premium is cleaner than regular gas..now going to 92 or 94 octane which i have tried as well.. not much difference on mileage compare to premium but then again going higher octane really requires adj ur timing to about 10 -15 degree adv. then ull have better take off..and the rules of engagement is adj ment need the feel as well.. makes sure ur engine is not knockin' other wise ur too advance. retard bit by bit..

You cannot make such blanket statements....using premium and getting better milage or performance DEPENDS on the car you put it in, and is not necessarily the same result for all cars.

You run premium in your Yaris sewing machine motor, it will get worse milage, it will produce less power, and it will create more emissions, and burn dirtier. Leave the Premium for the cars that are engineered for it, high compression engines, higher performance cars....premium is not for our Yaris...save your money. Come on guys, get real!

[Kaotic Lazagna]

My mileage goes to crap at 80+. I get the best at 70 or so. 37-38 mpg is the best I have ever gotten.

that's good for going 70 mph.

[Kaotic Lazagna]

does premium in, say, Chevron gas, have more cleaning additives?

[eTiMaGo]

does premium in, say, Chevron gas, have more cleaning additives?

I believe the question should be, are those "cleaning additives" and othe rmagical things you pay for in fancy fuels anything more than marketing gimmicks? Is there any independent testing to show it actually does anything?

Don't ya just love capitalism? :biggrin:

[marcus]

our yaris can run 87 octane or more obviously higher the octane the cleaner it is..it doesnt mean you cannot use more than 87.. its saying the lowest grade you can use is 87 but it does not limit it to 87..and i will guarantee you that you ll get better mileage on premium compare to regular..its jsut the matter of you spending a little bit more for premium.. go with experience and youll see..spend 40 buck or fill up the same liter regular compare to premium and youll see that marcus is right.. oh yah by the way sum cars cannot take 87..most honda is premium and UP!

You cannot make such blanket statements....using premium and getting better milage or performance DEPENDS on the car you put it in, and is not necessarily the same result for all cars.

You run premium in your Yaris sewing machine motor, it will get worse milage, it will produce less power, and it will create more emissions, and burn dirtier. Leave the Premium for the cars that are engineered for it, high compression engines, higher performance cars....premium is not for our Yaris...save your money. Come on guys, get real!

[Kaotic Lazagna]

I believe the question should be, are those "cleaning additives" and othe rmagical things you pay for in fancy fuels anything more than marketing gimmicks? Is there any independent testing to show it actually does anything?

Don't ya just love capitalism? :biggrin:

yeah, i've always wondered that too, but seeing how Shell, Chevron, and the other companies that say they have these "cleaning additives" perform better than those el cheapo gas, i slowly started thinking less about it.

[Kaotic Lazagna]

our yaris can run 87 octane or more obviously higher the octane the cleaner it is..it doesnt mean you cannot use more than 87.. its saying the lowest grade you can use is 87 but it does not limit it to 87..and i will guarantee you that you ll get better mileage on premium compare to regular..its jsut the matter of you spending a little bit more for premium.. go with experience and youll see..spend 40 buck or fill up the same liter regular compare to premium and youll see that marcus is right.. oh yah by the way sum cars cannot take 87..most honda is premium and UP!

my experience with premium, except this one, was that my mpg actually was less than average.

which Honda's are you talking about? aside from the upper-end Honda's i would think that they could take regular.

[marcus]

well i guess the honda si.. uses premium or up.. and that is odd where ur getting less mile on premium compare to regular..dont get me wrong..about faster burning fuel which is regular compare to premium..just going by my personal experience with my cars...maybe i wouldnt know unless i buy an expensive cars out there..

my experience with premium, except this one, was that my mpg actually was less than average.

which Honda's are you talking about? aside from the upper-end Honda's i would think that they could take regular.

[Kaotic Lazagna]

the more expensive cars that i've had got less mpg. then again, the Camry and GTI used always used plus with a tank of premium once-in-a-while, unlike my Yaris, all regular except that one time.

[marcus]

try filling up with regular and track km or mile then fill up with premium...the car i drove which is cavalier full tank regular run me about 330 km then switch to premium im constantly running over 360... my celica regular will run the same 310-320 with premium 360-370..and im doint same thing week after week..work to friends houses...


the more expensive cars that i've had got less mpg. then again, the Camry and GTI used always used plus with a tank of premium once-in-a-while, unlike my Yaris, all regular except that one time.

[Kaotic Lazagna]

i don't want my Yaris to get used to premium, so i'll test it out again in a month, or when ever the gas prices goes down a bit. premium can get close to 4 bucks here.

[marcus]

convert to diesel!!!!!!!!lolz....

[Kaotic Lazagna]

lol...don't know why, but diesel is sometimes more expensive than regular.

[Pavel Olavich]

our yaris can run 87 octane or more obviously higher the octane the cleaner it is..it doesnt mean you cannot use more than 87.. its saying the lowest grade you can use is 87 but it does not limit it to 87..and i will guarantee you that you ll get better mileage on premium compare to regular..its jsut the matter of you spending a little bit more for premium.. go with experience and youll see..spend 40 buck or fill up the same liter regular compare to premium and youll see that marcus is right.. oh yah by the way sum cars cannot take 87..most honda is premium and UP!

Marcus, do you know how octane works? It RETARDS the combustion...why would you do that with a tiny low compression Yaris motor? I think you're still holding on to old Grandpa logic, which dictates that using premium means higher MPG, and lower emissions...this is false unless the car is tuned for the higher octane...you use Octane 93 or 94 in your Yaris you will get lower MPG, and less power from the motor...it is not tuned for higher octane....say goodbye to old thinking....it no longer applies these days. And you're wrong again, most Honda's use regular 87, NOT premium.

[Pavel Olavich]

try filling up with regular and track km or mile then fill up with premium...the car i drove which is cavalier full tank regular run me about 330 km then switch to premium im constantly running over 360... my celica regular will run the same 310-320 with premium 360-370..and im doint same thing week after week..work to friends houses...


THAT IS A CAVALIER!!!! How can you assume that what works for a Cavalier will work with a Yaris?!? :iono:

[marcus]

hey its not just the cav its the celica gts, 94 honda civic si, mitsubishi lancer es., 95 acura integra, camry 95.., want me to go on... but hey use 87 its ur car...all that matter is physical evidence...its kinna like a dead guy teling you how he got killed using forensic .

THAT IS A CAVALIER!!!! How can you assume that what works for a Cavalier will work with a Yaris?!? :iono:

[Pavel Olavich]

Marcus,

2006 Mustang, 2007 Yaris, 2003 Expedition, 2002 Camry, 2004 Camry, 2005 Civic...these ALL get worse gas milage when using premium....but these are not Yaris, so this list and YOUR list is irrelevent.

All cars, regardless, will get better milage when one uses the octane the car was tuned for...this is the optimum for best performance.

The Yaris will get worse milage with Premium...it's sad that superstitions die hard....

Stop listing other cars....lets talk about the Yaris.

YARIS!

[marcus]

pavel,
im not sure how they tune your car there in cali...but in here with the cold weather the slower the burn of fuel the extra hp on the car...extra boost on hp reaches distance faster...its works for yaris rs, yaris s, yaris package a, yaris package b, yaris yr, yaris yaris yaris yaris yaris...........lolz :) :) :)


Marcus,

2006 Mustang, 2007 Yaris, 2003 Expedition, 2002 Camry, 2004 Camry, 2005 Civic...these ALL get worse gas milage when using premium....but these are not Yaris, so this list and YOUR list is irrelevent.

All cars, regardless, will get better milage when one uses the octane the car was tuned for...this is the optimum for best performance.

The Yaris will get worse milage with Premium...it's sad that superstitions die hard....

Stop listing other cars....lets talk about the Yaris.

YARIS!

[Go4th]

Pavel Olavich have you really already made 135 posts since you joined at
03-19-2007, 11:41 AM

wow....... :eek: :clap: :respekt:

[Edd]

Your regular is only 87?

Ours:
Regular - 92
Premium - 95
Optimax™/Ultimate™ - 98 (The name is different with each company)

EDIT: Apparently the number is calculated differently and the fuel is the same thing - shown here. (http://en.wikipedia.org/wiki/Octane_rating)

[marcus]

canada
regular = 87
premium = 89
gold = 91
sunoco= 94 highest..


Your regular is only 87?

Ours:
Regular - 92
Premium - 95
Optimax™/Ultimate™ - 98 (The name is different with each company)

EDIT: Apparently the number is calculated differently and the fuel is the same thing - shown here. (http://en.wikipedia.org/wiki/Octane_rating)

[Dragonacc]

I agree with the others on that say higher octane will not give better fuel economy (unless the ecu changes the tune because of it). There are a limited number of cars out there that have ECUs that will adjust the tune of the car based on the octane of the fuel.

Usually the ECUs that have this feature only actually work in reverse. They change the tune when you put lower octane fuel in and it hurts performance and fuel economy. This is because those cars were designed to use higher octane fuel to begin with.

Anyone that says their car get better mileage with premium is probably just driving it better because they just got raped at the pump.

[marcus]

i think im getting what other people are sayin..only because you guys already are using 89 and above so it doesnt make the diff..in fact u may lower ur gas mileage as well..in canada yaris is running on 87 octane gas..and 90 % of cars out here.. big difference on 87 to 89 without any exaguration ull notice the diff right away swiching to 89..gas mileage is actually higher with the 89 octane gas..and that is based on my experience with multiple differents cars out here...then again i dont drive high end cars..bmw,lexus,infiniti..etc....

[ChinoCharles]

Aren't there some warranty issues with putting 93 octane fuel in a car rated for 87 from the factory? You guys putting high-grade fuel in Yarii better hope we don't find out later on that she doesn't like it. Fuel systems aren't cheap.

[marcus]

you may need to ask ur dealer all i know is it should run atleast 87 octane or up..it didnt say just use 87. then again 93 octane has no diff with 89..the only time it will make the difference is you adjusting or advancing ur timing and that will give you faster acceleration..make sure its not too advance...but the only thing that i dont know is if the yaris ecu will automatically bring the timing down again after you advance it..:thumbup:

Isn't there some warranty issues with putting 93 octane fuel in a car rated for 87 from the factory? You guys putting high-grade fuel in Yarii better hope we don't find out later on that she doesn't like it. Fuel systems aren't cheap.

[marcus]

Advance timing requires higher octane gas..otherwise ur engine will knock..i have been doing this on my celica for the past 6 years it gives me faster take off with 94 octane from sunoco..but uses more gas though..then i bring it down on winter...1 bolt on the cam to adj. takes less than 2 minutes.. timing gun nessesary..

[ChinoCharles]

OK, so I can go put 110 octane in it? :laugh:

[marcus]

whoah easy there chino... might as well put sum jetfuel in there....i dont know how much tadvance timing can our yaris take though...check advance timing thru google.. maybe itll tell you... easy on the engine its only 1.5l....:smile:


OK, so I can go put 110 octane in it? :laugh:

[ChinoCharles]

You said 87 or higher! Does it take 87 or does it take 87-93 or does it take 87 or higher?!

[:bellyroll:]

[marcus]

87 or higher but the max here is 94 octane.. im assuming higher than 94 may not be good for the engine..but you dont really wanna do that do you..94 with proper advance timing will work ive run 94 on my celica and its fine.. faster acceleration..but uses gas like an alcoholic..

[Go4th]

Why don't people trust what the engineers/designers of Toyota say to put in your car by what they posted in the car manual?

Don’t you think that they have already designed the car specifically for what they put in the manual?

You don’t think they have already done all the research that we are unable to do; that’s why there is always debates about it.

Look in your manual and find the cheapest gas station around and put that octane in there and save some money.

But if your bound and determined to waste money on gas for a non performance car that you should not be revving and zooming around town like you would in a 350Z then:
go to the gas station you like best (Chevron, Amoco/BP. Shell, CITGO, etc.) and waste the extra money on your reliable name brand gas that you believe in for the octane rated gas that is in your manual.

Just don’t waste it on higher octane because someone else has already researched it and is telling you in your manual what to put in your car.

And of course I am not speaking to anyone who has made engine mods…

[marcus]

87->94...... we aint got any higher than 94....if it was me 889 is good any higher requires advance timing for you to benefit from it...

You said 87 or higher! Does it take 87 or does it take 87-93 or does it take 87 or higher?!

[:bellyroll:]

[marcus]

well as what we discussed b4 i believe you guys down there starts with 89 octane on the other hand we start on 87.. 89 is good no higher needed although higher octane extra boost again requires advance timing..company made theyre car to run atleast on 87 octane gas...if you ask me the cleaner the gas the better and i can tell you this 87 aint clean at all..that when you get all your deposit inside ur engine bro.. and shorten the life or ur fuel filter as well.....there is a noticeble diff between 87 to 89 but 89 - 94 requires advance timing to benefit for it!!!!!!!!!!!!!!!!!!!!!!!:burnrubber:

Why don't people trust what the engineers/designers of Toyota say to put in your car by what they posted in the car manual?

Don’t you think that they have already designed the car specifically for what they put in the manual?

You don’t think they have already done all the research that we are unable to do; that’s why there is always debates about it.

Look in your manual and find the cheapest gas station around and put that octane in there and save some money.

But if your bound and determined to waste money on gas for a non performance car that you should not be revving and zooming around town like you would in a 350Z then:
go to the gas station you like best (Chevron, Amoco/BP. Shell, CITGO, etc.) and waste the extra money on your reliable name brand gas that you believe in for the octane rated gas that is in your manual.

Just don’t waste it on higher octane because someone else has already researched it and is telling you in your manual what to put in your car.

And of course I am not speaking to anyone who has made engine mods…

[marcus]

ok update.. now all this info is based on an old car old engine..did a couple of research and found out that newer cars computer will adj automatically which wont matter if regular 87 octane is used or 89... mah bad although this does work on older engine thats why based on my own experience older engine benefit from higher mileage on premium..ecu not advance enuff to compensate for it.. so you guys are right 87-89 wont make a difference.. with the new engine...but still even with the new engine higher octane with proper timing will definetely make a difference...just dont know if computer will make adj as well....???????????????????

[Black Yaris]

yes our car can tell the difference between fuel grades... more premium gas gets better gas mileage... plain and simple... if you do not believe me just do it.... then you will know for yourself

[marcus]

:iono: :iono: :iono: :iono: :iono: :iono: :iono: :iono: :iono: :iono: :iono:
i dont know anymore im just raising my post rate in here and ur helping me do it with your repetetive question..lolzz :laughabove: :bellyroll: :bellyroll:

You said 87 or higher! Does it take 87 or does it take 87-93 or does it take 87 or higher?!

[:bellyroll:]

[churp]

Just went from 87 to 89 yesterday and from the but dyno says the car feels better! I agree with Black Yaris better octane = better performance and milage. Anyone who considers the Yaris engine as only a bare bones economy engine needs to use a little more grey matter.....this is a 'small' displacement, precision, high output motor---compare it to any US of A motor (do they have VVT and 10.5:1 compression?), synthetic oil and quality gas definately help, not hurt this engine. A few people seem to have researched this, but most are just talking here. Eventually someone will use the scangauge and show some results, and I'm betting my gut feeling, backed by 30+ years of engineering experience and being a car nut since I was 10, are right.

Until then...its all BS :bs:

[Kaotic Lazagna]

wow, i didn't think all this debating would arise. but yeah, i think i'll stick to regular for now, and "clean" it out with premium every once-in-a-while, or when it's "cheap". and of course, Chevron only.

[Black Yaris]

Shell only here and 89+ on the octane

[Kaotic Lazagna]

so the lowest grade you'll get is "plus"?

[Black Yaris]

well every once in a great while I hit the 87 button on accident out of habbit from previous cars.... and car gets less MPG... but to answer your question, yes

[ChinoCharles]

I only use jet fuel.

[Kaotic Lazagna]

well every once in a great while I hit the 87 button on accident out of habbit from previous cars.... and car gets less MPG... but to answer your question, yes

heh, plus is what i used to use in the GTI, and we use plus in the Camry.

[Kaotic Lazagna]

I only use jet fuel.

heh, what about the fuel they use in Funny Cars? alcohol or something, right?

[Black Yaris]

here is Chino's last car
http://www.ronpatrickstuff.com/images/AB12_15_05copy.jpg

[Kaotic Lazagna]

lol...that Bug's ass is on fire!

[Black Yaris]

http://www.ronpatrickstuff.com/
ya'll gotta check the site it got this from out

[Kaotic Lazagna]

DAMN!

[Go4th]

that site is great!

[Black Yaris]

who will be the first to have a jet propelled Yaris? Anyone live near that guy?

[Edd]

What the **** is up with people saying it is dangerous to go higher with octane? The manual gives you the LOWEST octane rating the car will run on. The higher the number, the better. There is no damage from going to a higher octane level - you are just putting in purer fuel.

[Black Yaris]

you are just putting in purer fuel.

wrong- higher octane has more additives

[BailOut]

The higher the number, the better. There is no damage from going to a higher octane level - you are just putting in purer fuel.

Octane is not a measurement of caloric content or burn-ability (cetane). It is a measurement of how high a temperature is needed in order to ignite the fuel. This is why premium fuel is usually only required on high performance engines (because they run at higher compression levels which generates more heat).

Higher octane fuel is actually less pure because of the extra additives which are used to make the fuel ignite at a higher temperature. These additives are also why it costs more.

Running fuel of an octane higher than what your engine is designed for can help with knock (detonation) but that is generally where the benefits stop. The detriments are:

- Fouled spark plugs due to the deposits left via incomplete burning.
- Greatly increased emissions due to incomplete burning.
- Fouled O2 sensors due to these emissions.
- Fouled catalytic converter due to these emissions.

Stick to what your engine is rated for. The 1NZ-FE engine in the Yaris is designed for 87 octane gasoline.

[churp]

Little bit of the subject but that is why all the early RX7's should run the least octane in the Wankel...slow burn and doesn't promote the carbon buildup problem the rotarys have. Thanks for refreshing my memories on the rotarys Bailout!

But I still believe the computer compensates to allow 87 octane when used....but a higher octane allows the computer to benifit from the 10.5: compression....:smile:

[ChinoCharles]

4265

Actually, that is my last car... and it was baller.

How many 5500 pound cars do you know that can yank a 14 second quarter mile with the heated leather seats on? :laugh:

[Kaotic Lazagna]

heh, that's one fast tank! hahaha

[Pavel Olavich]

yes our car can tell the difference between fuel grades... more premium gas gets better gas mileage... plain and simple... if you do not believe me just do it.... then you will know for yourself

Sorry but you're living in the land of dillusion...using octane higher then 87 for your Yaris will give you WORSE milage....why is this so hard for you to understand? Using higher octane means the combustion is RETARDED, meaning that it takes MORE gas to give the car the same power....this means lower milage...the only exception to this is if the car is engineered (tuned) for higher octane....you keep thinking that ALL cars behave the same with higher octane...this is dillusion, or worse.

[Pavel Olavich]

Octane is not a measurement of caloric content or burn-ability (cetane). It is a measurement of how high a temperature is needed in order to ignite the fuel. This is why premium fuel is usually only required on high performance engines (because they run at higher compression levels which generates more heat).

Higher octane fuel is actually less pure because of the extra additives which are used to make the fuel ignite at a higher temperature. These additives are also why it costs more.

Running fuel of an octane higher than what your engine is designed for can help with knock (detonation) but that is generally where the benefits stop. The detriments are:

- Fouled spark plugs due to the deposits left via incomplete burning.
- Greatly increased emissions due to incomplete burning.
- Fouled O2 sensors due to these emissions.
- Fouled catalytic converter due to these emissions.

Stick to what your engine is rated for. The 1NZ-FE engine in the Yaris is designed for 87 octane gasoline.

AMEN Broda!!!! You wrote it right and it is right!!!!! Why some here hold on to superstitions, urban myths, or what use to work with 1960ish cars is beyond me.... :headbang:

[static808]

4265

Actually, that is my last car... and it was baller.

How many 5500 pound cars do you know that can yank a 14 second quarter mile with the heated leather seats on? :laugh:

hahah, my sienna does a 0-60 in 7.4, and the 1/4 mile in 16.4. not too bad for any car, let alone a van that seats 7!! my van is probably a little slower than those numbers, since i gots all the goods, like power doors and trunk and heated leather everything, and i run only the required 87. those tests were done using premium fuel. but i can attest to the fact that i've beaten quite a few cars "off the line" using only the required 87...now if we can only cram my sienna v6 into the yaris...

--B

[Black Yaris]

Sorry but you're living in the land of dillusion...using octane higher then 87 for your Yaris will give you WORSE milage....why is this so hard for you to understand? Using higher octane means the combustion is RETARDED, meaning that it takes MORE gas to give the car the same power....this means lower milage...the only exception to this is if the car is engineered (tuned) for higher octane....you keep thinking that ALL cars behave the same with higher octane...this is dillusion, or worse.

ok Pavel, MR HIGH and MIGHTY.... you explain why it is that everyone that tries putting higher octane fuel in there Yaris gets better gas mileage? In the words of ChinoCharles "Don't you ever shut up?"

[marcus]

hehehe thats funny...

[marcus]

premium is always cleaner that the regular.....it may not make much to the horsepower but its cleaner..

[Moose]

I tried a tank of premium this week, after reading this thread, just to see what would happen. 90% of my driving is usually highway, and half of that is in bumper to bumper traffic. I usually average about 35 mpg. Using the premium, and with a 120 mile mountain run (most of which was spent at 4500 rpm and above) in addition to my normal routine, I averaged 37 mpg.

Will I spend the extra money on premium again? Nah, it wasn't that much of a difference to me. Did it prove to me that you do, in fact, get better fuel economy with 93 octane? You betcha, and I bet that I could've done better without the mountain run, as well.

[Kaotic Lazagna]

I tried a tank of premium this week, after reading this thread, just to see what would happen. 90% of my driving is usually highway, and half of that is in bumper to bumper traffic. I usually average about 35 mpg. Using the premium, and with a 120 mile mountain run (most of which was spent at 4500 rpm and above) in addition to my normal routine, I averaged 37 mpg.

Will I spend the extra money on premium again? Nah, it wasn't that much of a difference to me. Did it prove to me that you do, in fact, get better fuel economy with 93 octane? You betcha, and I bet that I could've done better without the mountain run, as well.

cool, cool, this premium stuff is weird.

[Pavel Olavich]

ok Pavel, MR HIGH and MIGHTY.... you explain why it is that everyone that tries putting higher octane fuel in there Yaris gets better gas mileage? In the words of ChinoCharles "Don't you ever shut up?"

So are you suggesting that the majority rules? Did you attend college? Simply put, they're wrong....sorry, but they are, and NO I never shut up.

[Pavel Olavich]

premium is always cleaner that the regular.....it may not make much to the horsepower but its cleaner..

So less efficient combustion means "cleaner"....Nope!

[Pavel Olavich]

I tried a tank of premium this week, after reading this thread, just to see what would happen. 90% of my driving is usually highway, and half of that is in bumper to bumper traffic. I usually average about 35 mpg. Using the premium, and with a 120 mile mountain run (most of which was spent at 4500 rpm and above) in addition to my normal routine, I averaged 37 mpg.

Will I spend the extra money on premium again? Nah, it wasn't that much of a difference to me. Did it prove to me that you do, in fact, get better fuel economy with 93 octane? You betcha, and I bet that I could've done better without the mountain run, as well.


Your 'test' was not scientific....did you every consider that you could fill your tank up with 87 octane and drive your same route 10 times and get ten different MPG results? Your test lacks controls to be able to draw conclusions. Funny how you do your test once, and draw conclusions....did you attend college?

[acrbill]

The Yaris has 10.5:1 compression. It must have a extremely conservative timing curve to allow the car to run on regular. My old Neon ran on premium. It said premium fuel recommended. It did not say required. If I put regular fuel in the MPG would go down like crazy and there would be a noticeable power loss.

IMO any car with that high of a compression ratio should run better with a slower burning fuel in. The real test would be to use a obd2 data logger to monitor the knock sensor and timing with regular and premium. I would bet that you will see a lot of activity from the knock sensor and therefor timing being pulled and fuel being dumped.

[Pavel Olavich]

The Yaris has 10.5:1 compression. It must have a extremely conservative timing curve to allow the car to run on regular. My old Neon ran on premium. It said premium fuel recommended. It did not say required. If I put regular fuel in the MPG would go down like crazy and there would be a noticeable power loss.

IMO any car with that high of a compression ratio should run better with a slower burning fuel in. The real test would be to use a obd2 data logger to monitor the knock sensor and timing with regular and premium. I would bet that you will see a lot of activity from the knock sensor and therefor timing being pulled and fuel being dumped.


It's not just about high compression....the amount of cubic liters comes into play....just because a small engine has high compression does not necessarily mean it requires premium....you need to take the size of the engine into consideration too. The bigger the displacement, the longer it takes for the fuel to burn completely, thereby requiring more octane to retard the burn for a given stroke.

[Black Yaris]

Your 'test' was not scientific....did you every consider that you could fill your tank up with 87 octane and drive your same route 10 times and get ten different MPG results? Your test lacks controls to be able to draw conclusions. Funny how you do your test once, and draw conclusions....did you attend college?

let us pull that Chino quote again "Do you ever shut up?"

[Slummy]

I know that acrbills test was not "scientific", but dont all his previous tanks that average 35 MPGs act as a control? Not trying to be difficult. Just curious.

[Black Yaris]

yes... Pavel is just mean, he just does not want to face the truth that he is WRONG 90% of the time

[elsteverino889]

Go with Citgo...support Chavez!!!....i kid lol

[churp]

:thumbup: Hey Pavel....you're great!!!

Haven't met many like you, but all I can think of is you sittin at home gettin under peoples skin and just laughin!! :thumbup:

:headbang: Carry on.

[Black Yaris]

:thumbup: Hey Pavel....you're great!!!

Haven't met many like you, but all I can think of is you sittin at home gettin under peoples skin and just laughin!! :thumbup:

:headbang: Carry on.

:thumbdown: 1 vote to ban you from the site just for that comment :biggrin:

[churp]

Gotta be the the why.........couldn't be serious!!!!

[Black Yaris]

Gotta be the the why.........couldn't be serious!!!!

What? Please edit, that does not make sense

[acrbill]

:thumbdown: 1 vote to ban you from the site just for that comment :biggrin:

Just what any site needs. Some 8 year old who gets off by pissing everyone off.

99% of the time I would agree with Pavel, but the high compression makes this situation different than most.

By your logic you would lose MPG. So even that guys "unscientific" test points to that not being the case.

So everyone knows.

The higher the octane the slower the burn. You want the lowest octane that the car can function well at. Most of the time using higher than needed octane cost performance. With higher compression there is an increased chance of engine knock. Not even the audible type, just the type that the knock sensor picks up. When that happens the ECU pulls timing and in some cases dumps fuel. Both are bad for all aspects of performance.

The only real way to test would be to log sensor outputs and timing advance with both fuels.

[acrbill]

What? Please edit, that does not make sence

WTF is sence? That makes no sense.

I keed I keed.

[Black Yaris]

I bet those that are saying higher octane fuel does not give ou better MPG have never tried it... You will bash it every wich way and sideways, but untill you try it yourself, or as bill stated with the correct diag equipment stop bashing it, because you don't know.

[static808]

damn kaotic, look what you done started?? its right up there with the synth vs. dino debate. makes for fun reading though...

--B

[Kaotic Lazagna]

damn kaotic, look what you done started?? its right up there with the synth vs. dino debate. makes for fun reading though...

--B

lol...would have never thought i could start all this. :laugh:

[static808]

lol...would have never thought i could start all this. :laugh:

we need to keep you out of the UN. you mean well, but you'll be starting wars by accident!! :tongue:

--B

[Kaotic Lazagna]

hahaha, the United Nations...hmmm, perhaps, i might start WWIII if i join the UN. lol...

[Adriaan]

personally i like the premium gas, i've has lots of problems with the regular gas here in ontario. The gas here is mixed with ethanol some times up to 15% except shell premium and i believe pioneer. i was having problems with the gas sensor. Took it to the dealer to find out that the since i was mixing fuel with and without ethanol the fuel turned a white color and had damaged the sensor. i work between montreal and toronto. In Montreal there is no ethanol in the fuel as of yet. Since i had it changed i stop buying regular here in ontario and haven't had the problem since. Also I work for esso and i found out that when you mix ethanol fuel like sunoco with regular fuel with out ethanol turns a white color, and as of yet there no technology to separate the two. But this is my experience and what i found out. Not sure if it is true with what i found, or my car was and isolated incident. Also i did a test with sunoco ultra 94 and shell premium on my last trip to montreal. Between my monteal house and toronto house is 686km with ultra 94 i got 536km and with shell i got 636km same driving style going and return about 120km to 140 km on the 401.

[marcus]

as per (Adriaan's) quote.
"he personally i like the premium gas, i've has lots of problems with the regular gas here in ontario. The gas here is mixed with ethanol some times up to 15% except shell premium and i believe pioneer. i was having problems with the gas sensor. Took it to the dealer to find out that the since i was mixing fuel with and without ethanol the fuel turned a white color and had damaged the sensor. i work between montreal and toronto. In Montreal there is no ethanol in the fuel as of yet. Since i had it changed i stop buying regular here in ontario and haven't had the problem since. Also I work for esso and i found out that when you mix ethanol fuel like sunoco with regular fuel with out ethanol turns a white color, and as of yet there no technology to separate the two. But this is my experience and what i found out. Not sure if it is true with what i found, or my car was and isolated incident. Also i did a test with sunoco ultra 94 and shell premium on my last trip to montreal. Between my monteal house and toronto house is 686km with ultra 94 i got 536km and with shell i got 636km same driving style going and return about 120km to 140 km on the 401."

So less efficient combustion means "cleaner"....Nope!

[dallas]

Let's stop the b.s and start posting our mileage figures on the two grades of gas. Enough people checking it should make the results more believable:iono:

[marcus]

well i have been switching from prem to reg... so far i got more mileage with the prem then again that could also be driving habit as well..but its about 10-30 km difference for about 38 liters of gas..

here:

1st tank 540km with 39.8l fill up = 38.34mi/gal with regular 87 octane
2nd tank ran 535km fill up 38.4l = 39.37mi/gal with premium 89 octane
3rd tank 540km 37.5l fill up=40.69mi/gal with premium 89 octane
4th tank 570km premium fill up @38.00 liters =42.40 m/gal -15km/liter 89 octane
5th tank went to regular gas..48.2 liters ran 711 km 40% hwy (had to add 10 liters in between), calculated about 6.7l /100km,,41.68m/gal ... i was expecting about 6.0 l/100,,,atleast...

[jdium]

[QUOTE=fu_im_from_texas;69779]

not sure why either. my factors remaind the same, for the most part. the only difference is that i was driving faster and the gas itself. but i'm not willing to get another tank of premium to find out. lol...:laugh:

I'm doing some math...the Yaris has an 11 gallon tank..."premium" 93 octane gas is usually .20 cents more per gallon than "regular" 87 octane gas...that's $2.20 a tank...

If you get 10% better gas mileage with premium, as some have stated (36mpg with regular, 40mpg with premium, etc), then you will be driving as far on 10 gallons or premium as you would be on 11 gallons of regular...

Stop me if I'm losing anyone...

Gas is now above $3 a gallon around my area. You are saving .80 cents if you see 10% better mileage with premium...

I'm thinking this is along the lines of the placebo effect, you believe your more expensive purchase is going to help you, so it does...

Also, how much do you all drive if an extra $2.20 a tank for premium is breaking your wallet? If you drive 10,000 miles a year at 40 mpg, that is about 23 fillups. That is $50 a YEAR...

Sorry for the ramble...but if you believe that premium is helping you, buy it. Scientifically, there is no benefit to running premium in these cars...

[churp]

[QUOTE=Kaotic Lazagna;69781]

......

Sorry for the ramble...but if you believe that premium is helping you, buy it. Scientifically, there is no benefit to running premium in these cars...

Don't understand how you can say that! Scientifically, under load the higher octane allows more timing advance before knock (in a 10.5:1 compression ratio car) which is more efficient, using less fuel for the power needed....not under load I agree with you.

[Kaotic Lazagna]

hey, i never said that. hahaha...why is my name highlighted and not jdium?

but yeah, this thread was brought back from the dead. well, i used premium again and got less mpg. but i know that's because i've been using the a/c more. personally, i think i'm just going to stick regular.

[jdium]

[QUOTE=jdium;101220]

Don't understand how you can say that! Scientifically, under load the higher octane allows more timing advance before knock (in a 10.5:1 compression ratio car) which is more efficient, using less fuel for the power needed....not under load I agree with you.

It is a 105 hp engine, it is ALWAYS under load :D

If what you say is true, why don't the Toyota engineers tell us to use premium?

[eTiMaGo]

maybe because it would turn potential buyers away from the car, you don't usually associate a modern economy car with premium gasoline... Just a guess anyway! I'm gonna try higher octane fuel just for the heck of it for my next tank...

[njyaris]

just my two cents ... i just bought my YARIS a week ago and I LOVE IT .. therefore i use 93 octane .. now does this change anything .. ofcoarse it does .. even if it's only perception .. since my perception is in favor for better gas milage and higher performance i tend to drive a little harder and faster .. just my two cents

[jdium]

just my two cents ... i just bought my YARIS a week ago and I LOVE IT .. therefore i use 93 octane .. now does this change anything .. ofcoarse it does .. even if it's only perception .. since my perception is in favor for better gas milage and higher performance i tend to drive a little harder and faster .. just my two cents

Your perception is for better gas mileage so you drive harder??? That's counter productive...

Like I stated above. The higher mileage being noted is IMO a placebo type effect. You think higher octane will help, thus it does.

If requiring higher octane would turn away potential buyers, why not atleast tell them what everyone in here is saying? Increased octane = increased mpg? Cuz it's not true...

[smokinyaris]

so do you guys feel up with premium or regular............

[jdium]

so do you guys feel up with premium or regular............

I feel up my girlfriend sometimes :drool:

I fill up with regular, the cheapest stuff I can find...

[forpinks]

Go buy a "Maximum Boost" book and it will tell you that a higher octane gas will give you more power compared to lower octane gas.

there is a comparison on the N/A and Turbo there really is a big difference especially if your running RPMs higher than 4500 on N/A... The turbo with high octane gas is damn more powerful than low octane.

Also the 106HP (not high performance? I know.) is achieved using high grade high octane gasoline for testing (Since Japan don't have anything lower than 93 octane they even have 120-125 octane) the engine power will drop to 100flywheel HP when you use 87 gas and it will make more gunk to the engine because of the slight combustion difference even with the knock sensors, remember the 1NZ-FE is japan made and tested so It should run 90+octane and will get 51MPG elsewhere except US (may be possible with acetone) which don't have anything higher than 93 basic fuel 100 octane cost like 4.30 vs 3.30 91...

(It's new here in the USA and Toyota USA wouldn't put the 91 reccomended fuel since it will hurt sales...)

Hope this helps!!!

[forpinks]

I used 87 on a 3.8 Chrysler rental van (1000miles ODO) with 6 passengers and an icebox and I have to absolutely floor it to go 75MPH uphill at I-15... when we went back (got mad with the slow climbing speed) and bought damn 91 eventhough it's a rental and I did'nt regret it since I can climb a hill at 85-100MPH (still floored) running with an IS with a radar detector.

All I can say is I am definitely satisfied of the 91octane gas even if I pay the high price!

[jdium]

Go buy a "Maximum Boost" book and it will tell you that a higher octane gas will give you more power compared to lower octane gas.

there is a comparison on the N/A and Turbo there really is a big difference especially if your running RPMs higher than 4500 on N/A... The turbo with high octane gas is damn more powerful than low octane.

Also the 106HP (not high performance? I know.) is achieved using high grade high octane gasoline for testing (Since Japan don't have anything lower than 93 octane they even have 120-125 octane) the engine power will drop to 100flywheel HP when you use 87 gas and it will make more gunk to the engine because of the slight combustion difference even with the knock sensors, remember the 1NZ-FE is japan made and tested so It should run 90+octane and will get 51MPG elsewhere except US (may be possible with acetone) which don't have anything higher than 93 basic fuel 100 octane cost like 4.30 vs 3.30 91...

(It's new here in the USA and Toyota USA wouldn't put the 91 reccomended fuel since it will hurt sales...)

Hope this helps!!!

Ignorance is bliss eh? Higher octane will NOT give you more power in a Yaris. Go buy some dyno time if you can't believe me. It will NOT give you higher mpg either. Put the car on jack stands, and idle a tank away of each if you can't believe me either.

On a turbo car, higher octane allows more boost, thus higher hp.

Knock sensors have nothing to do with engine "gunk" buildup.

If it was possible for the Yaris to get 51 mpg in the U.S., it would. Why would Toyota not want a car that destroys every other car in its class? Try 51 kpg maybe.

The Yaris is sold in America. I think the Toyota engineers are smarter than us.

[churp]

Ignorance is bliss eh? ......
On a turbo car, higher octane allows more boost, thus higher hp.

...... I think the Toyota engineers are smarter than us.

I'm sure the Toyota engineers aren't any dumber than us. That is why they say the Yaris run's with 87 octane, and that is why cars have had ECU's installed for the last few decades....don't you believe there is a reason...it's not because they cost a lot. They allow the timing to be retarded in a load situation to prevent knocking with the high compression engines (above 9 to 1 compression) in a load situation like maintaining 60-70 mph up a steep hill while using 87 octane.....this is not the optimum timing for power or gas milage but it keeps the engine from self destructing.

My 53 Buick I used to have, had no timing marks. The shop manual said to said to set timing by turning the distributer until it ran good, then test drive by accelerating or going up a hill. If there was a knock go back and retard the timing,then repeat until only a very faint knock was heard. This is fine and dandy until you got a batch of poor gas, then it would knock like crazy. You could increase milage by advancing timing (set according to the gas you used) and driving consertively. ECU's have changed this to the better, but 'good' gas does work.

During slow acceleration or maintaining speed on flat land the ECU allows the optimum timing because knock isn't present (even with 87 octane).....most hypers drive in this condition 99.9% of the time while the common everyday driver is in this condition 95% (guesstimate at maximum). So theoreticaly, scientifically, or any other way you think about it....the very concientious driver sees no gain from higher octane, the common driver may see better milage on a small fraction of their driving, and the leadfoot would see the best gains. Granted this is a small percentage gain over a very small percentage of a persons driving....but it is a gain.

[forpinks]

^^^ Go to Toyota Canada.... it clearly states that it gets 41MPG city and 51MPG highway they measure fuel economy in metric using L/100KM and they don't use KPG, also they have high octane gas to give you better fuel economy...

Don't be a cheapo and face the truth that higher octane gasoline performs better!

(Why does the US form 87 octane anyway? are they the only ones and want to be unique?) I even tried octane 125 at the airport for my AE92 and it definitely cleansed the engine and gave better power and response I drove it like I stole the damn thing.... (one thing I noticed is that the cold engine start white smoke disapeared when I used a tank of 125octane)

I'm gonna try half a tank of octane 100 for the tC and see if it does something nice.

[njyaris]

87 is for lawnmowers .. you decide! :thumbsup:

[fu_im_from_texas]

... I think the Toyota engineers are smarter than us.

:clap: ...toyota has spent 100s of 1000s of dollars looking at these issues. toyota says use 87 ... end of argument...

[WRBlue]

Also the 106HP (not high performance? I know.) is achieved using high grade high octane gasoline for testing (Since Japan don't have anything lower than 93 octane they even have 120-125 octane) the engine power will drop to 100flywheel HP when you use 87 gas and it will make more gunk to the engine because of the slight combustion difference even with the knock sensors, remember the 1NZ-FE is japan made and tested so It should run 90+octane and will get 51MPG elsewhere except US (may be possible with acetone) which don't have anything higher than 93 basic fuel 100 octane cost like 4.30 vs 3.30 91...

The rest of the world measures octane different than us in North America. In the EU and Australia, they advertise RON. Here we use an average of RON and MON. MON is a lower number than RON. YOU CAN'T COMPARE OCTANE RATINGS BETWEEN NORTH AMERICA AND THE REST OF THE WORLD.

The ignorance in this thread makes my head hurt.

Octane only measures the autoignition characteristics of gasoline. How easily it will explode without a spark.

THE ONLY THING THAT WILL CAUSE MPG TO INCREASE ARE O2 READINGS.

If the O2 sensor reads the car running rich, it'll lean it out within safe parameters. Lean = less fuel used = higher MPG.

HIGHER OCTANE DOES NOT CHANGE THE AIR-FUEL MIXTURE.

Higher octane gasoline can only prevent detonation. If your detonating with 87 octane, something is wrong with your engine/ECU.

A car runs a base timing and advances or retards it only within set parameters. And those parameters are ones set by Toyota Engineers as to be safe with low octane gasoline. The computer will not exceed those if you put high octane gas in and magically the computer knows.

Besides, there is no sensor that can tell what octane is used. To measure octane, you have to find out the percentage of volume is iso-octane and the percentage of volume is heptane. NO production car has the ability to do that...

And anyway, advancing timing does not cause less fuel to be used. It cause more power to be made from the fuel.

Everything else in this thread is anecdotal evidence. There are many, many, many variables. Elevation, wind, drag, tires, air pressure, surface type, load, weight, etc. The most important thing is repeatability. If you REALLY want to prove higher mileage, rent a couple weeks of dyno time in a lab. Control all the environmental variables to be constant for the whole week (temp, humidity, air flow, tire pressures). Empty the car 100% of all gasoline. put a predetermined mass of fuel in the car of a certain octane. Run about 40 tests and take the mean. IIRC 40 is the number where statistically each incremental test after that does not statistically significantly change the mean. Now change the octane and repeat all 40 tests.

Then and only then you can make assumptions if octane can change MPG.

[fu_im_from_texas]

The ignorance in this thread makes my head hurt.




...a keyboard and a strong opinion make me an expert on this topic ;)






Everything else in this thread is anecdotal evidence. There are many, many, many variables. Elevation, wind, drag, tires, air pressure, surface type, load, weight, etc. The most important thing is repeatability. If you REALLY want to prove higher mileage, rent a couple weeks of dyno time in a lab. Control all the environmental variables to be constant for the whole week (temp, humidity, air flow, tire pressures). Empty the car 100% of all gasoline. put a predetermined mass of fuel in the car of a certain octane. Run about 40 tests and take the mean. IIRC 40 is the number where statistically each incremental test after that does not statistically significantly change the mean. Now change the octane and repeat all 40 tests.

Then and only then you can make assumptions if octane can change MPG.

great idea for a test...but even if someone does perform a scientific experiment i, for one, am not willing to let the statistical facts get in the way of my own strong opinion (sarcasm intended!)

:clap: ...toyota has spent 100s of 1000s of dollars looking at these issues. toyota says use 87 ... end of argument...

toyota has already performed these experiments....toyota recomends 87...

:barf:

[churp]

You must have a different owners manual, mine states:

SELECT OCTANE RATING 87 (RESEARCH OCTANE NUMBER 91) OR HIGHER.

This is page 178 in my owners manual. Obviously they know what a few of us are trying to pass on here!!!!!!!!!!!!!!! :thumbsup:

The tests have been done before higher octane was ever put on the market (probably the 30's). The ECU has taken the "must have" higher octane in your car away....but it hasn't removed the fact that performance and milage will improve in most engines with it. Note that I am not saying it is cheaper to put the higher octane in....but where I live it's very feasable (Iowa and South Dakota 89 octane is the same price or cheaper than 87, and in Minnesota I get 89 for 2 cents more than 87) and I use 89 octane.

[blacksan]

Ok, I got it now.

[jdium]

The tests have been done before higher octane was ever put on the market (probably the 30's).

lol. Ya. Back when everything ran on leaded gas...

my head hurts...

[churp]

lol. Ya. Back when everything ran on leaded gas...

my head hurts...

Don't quite understand:confused: Cars ran on unleaded in the US until 1970. I'm pretty sure sex was even invented by then!

No, I'm actually positive first hand, sex was invented before 1970.

[jdium]

Don't quite understand:confused: Cars ran on unleaded in the US until 1970. I'm pretty sure sex was even invented by then!

No, I'm actually positive first hand, sex was invented before 1970.

Which brings me to my other point, don't smoke crack...:iono:

Most every gas was LEADED (no UN) before 1970. Leaded gas has a realative octane rating of todays "race' gas, like 110 or something...

[Moose]

Your 'test' was not scientific....did you every consider that you could fill your tank up with 87 octane and drive your same route 10 times and get ten different MPG results? Your test lacks controls to be able to draw conclusions. Funny how you do your test once, and draw conclusions....did you attend college?

WOW. I just saw this.

Is this guy still here, or has he been banned?

1) ...did you every consider that you could fill your tank up with 87 octane and drive your same route 10 times and get ten different MPG results?

Yes, and they are usually within .3-.5 MPG each time. I actually do the math and keep a log. That's as close to scientific as we can get.

2) Your test lacks controls to be able to draw conclusions.

As does your opinion.

3) ....did you attend college?

Yes, Georgia Tech. I actually know the science- you think you know the science. And don't try any cute comebacks- I'll just look at my degree and my paycheck and giggle.

Will there be anything else Pavel? I generally reserve arguing on the internet for times when I have nothing more adult to do, but watching you unravel and make a fool of yourself is worth it.

[WRBlue]

Unleaded gas didn't become common till the mid 80s. I remember when you had to hunt for the unleaded.

Leaded gas of the 70s was still 87 octane. Its just Lead is a knock detterant and so its a whole lot cheaper to make 87 octane with lead in it ;) . I'm not sure if the reason all the good race gas is leaded is cause its too expensive to make 110-120 octane without lead or if its actually impossible. You can get unleaded race gas up to about 100 or 102 octane...

[cali yaris]

{ OFF TOPIC }
As far as I know, sex was invented in 1976.

Uh... what was the topic about again?

(scrolling back to page one)

[Moose]

{ OFF TOPIC }
As far as I know, sex was invented in 1976.


Don't taunt the married animals. :bellyroll:

Sorry, I just don't like mean people- usually mean and idiot go hand in hand, so it's that much more maddening.

I'm done, I promise.

Back on topic.

[Kaotic Lazagna]

wow, my thread is going to start a war all over again.

[churp]

Which brings me to my other point, don't smoke crack...:iono:

Most every gas was LEADED (no UN) before 1970. Leaded gas has a realative octane rating of todays "race' gas, like 110 or something...

Wrong, read WRBlues post.

Thanks WRBlue for correcting me....1970 was when the compression ratio dropped in the US....along with performance.

[eTiMaGo]

well.. I filled up today, just for experimentation's sake, with 95 RON ethanol mix fuel. It's actually a good bit cheaper than 91.

Although, my methodology will be flawed, as I immediately took a (relatively) long drive. In my normal driving, I will see one bar drop after about 50-55km, but this is after a few days of short trips, after this one long trip (almost 100km), the bar dropped at around 80km into the tank. I drove at a steady 110-130km/h the whole way, as I had a passenger I could not really rev her up and see how the higher octane may affect the high RPM characteristics... I'll report more once I have better information to share :biggrin:

[Yarii]

They're not telling you to run higher octane... They're just putting the RON in brackets because the entire world except north america uses RON to measure octane. In NA our pumps are labled with the average of the RON and MON measurements, which is generally 4 or 5 points lower. 87 octane gasoline in north american is 91 RON.

You must have a different owners manual, mine states:

SELECT OCTANE RATING 87 (RESEARCH OCTANE NUMBER 91) OR HIGHER.

This is page 178 in my owners manual. Obviously they know what a few of us are trying to pass on here!!!!!!!!!!!!!!! :thumbsup:

The tests have been done before higher octane was ever put on the market (probably the 30's). The ECU has taken the "must have" higher octane in your car away....but it hasn't removed the fact that performance and milage will improve in most engines with it. Note that I am not saying it is cheaper to put the higher octane in....but where I live it's very feasable (Iowa and South Dakota 89 octane is the same price or cheaper than 87, and in Minnesota I get 89 for 2 cents more than 87) and I use 89 octane.

[Pavel Olavich]

WOW. I just saw this.

Is this guy still here, or has he been banned?

1) ...did you every consider that you could fill your tank up with 87 octane and drive your same route 10 times and get ten different MPG results?

Yes, and they are usually within .3-.5 MPG each time. I actually do the math and keep a log. That's as close to scientific as we can get.

2) Your test lacks controls to be able to draw conclusions.

As does your opinion.

3) ....did you attend college?

Yes, Georgia Tech. I actually know the science- you think you know the science. And don't try any cute comebacks- I'll just look at my degree and my paycheck and giggle.

Will there be anything else Pavel? I generally reserve arguing on the internet for times when I have nothing more adult to do, but watching you unravel and make a fool of yourself is worth it.

Your testing methods belie your "Georgia Tech" education. Sorry, but it was sloppy....by the way, I'm sure your giggling paycheck would make me laugh off my ass too!

[Moose]

http://jumi.lut.fi/~japalvia/pics/retard.gif

[Black Yaris]

The rest of the world measures octane different than us in North America. In the EU and Australia, they advertise RON. Here we use an average of RON and MON. MON is a lower number than RON. YOU CAN'T COMPARE OCTANE RATINGS BETWEEN NORTH AMERICA AND THE REST OF THE WORLD.

The ignorance in this thread makes my head hurt.

Octane only measures the autoignition characteristics of gasoline. How easily it will explode without a spark.

THE ONLY THING THAT WILL CAUSE MPG TO INCREASE ARE O2 READINGS.

If the O2 sensor reads the car running rich, it'll lean it out within safe parameters. Lean = less fuel used = higher MPG.

HIGHER OCTANE DOES NOT CHANGE THE AIR-FUEL MIXTURE.

Higher octane gasoline can only prevent detonation. If your detonating with 87 octane, something is wrong with your engine/ECU.

A car runs a base timing and advances or retards it only within set parameters. And those parameters are ones set by Toyota Engineers as to be safe with low octane gasoline. The computer will not exceed those if you put high octane gas in and magically the computer knows.

Besides, there is no sensor that can tell what octane is used. To measure octane, you have to find out the percentage of volume is iso-octane and the percentage of volume is heptane. NO production car has the ability to do that...

And anyway, advancing timing does not cause less fuel to be used. It cause more power to be made from the fuel.

Everything else in this thread is anecdotal evidence. There are many, many, many variables. Elevation, wind, drag, tires, air pressure, surface type, load, weight, etc. The most important thing is repeatability. If you REALLY want to prove higher mileage, rent a couple weeks of dyno time in a lab. Control all the environmental variables to be constant for the whole week (temp, humidity, air flow, tire pressures). Empty the car 100% of all gasoline. put a predetermined mass of fuel in the car of a certain octane. Run about 40 tests and take the mean. IIRC 40 is the number where statistically each incremental test after that does not statistically significantly change the mean. Now change the octane and repeat all 40 tests.

Then and only then you can make assumptions if octane can change MPG.


so the higher octane combined with vvt-i will not change fuel econ?:bs:
I ALWAYS get better mpg with premium fuel than 87... the only peple that deny the fact are the ones that have not tried it

[Black Yaris]

http://jumi.lut.fi/~japalvia/pics/retard.gif

where did you find that picture of Pavel?

[Moose]

where did you find that picture of Pavel?

Same place I found this one...
http://www.mattymo.com/albums/Stupid-Pictures/retard_prize.jpg

[Black Yaris]

did you get ahold of his family photo's?

[cleong]

I'm not taking sides, just relating personal experience.

Over here we have four grades of fuel at the service station, 92, 95, 98 and 98 Premium.

Each indicates a RON (which I understand to be different from the US). 98 Premium reputedly is the most "powerful" due to additional chemicals that boost power as well as clean up the engine (note that it is still listed as 98 RON).

Of the four, the only fuel that I have not sampled is RON 92. The other three I have tried, and found that 98 generally provides slightly better mileage than 95, although the price difference does not justify the mileage gained. 98 Premium is supposed to "burn" faster, therefore its mileage is actually poorer than regular 98 fuel. However it does seem to feel the most powerful of the three, having more eager throttle response and the engine sounding smoother.

[WRBlue]

so the higher octane combined with vvt-i will not change fuel econ?

Yes. Why would it?

[cleong]

Yes. Why would it?

Wouldn't a higher octane allow the engine to increase its timing and make more power, which means that less fuel is needed to maintain a given speed?

[Yarii]

Engine's don't detect the octane of fuel... They just retard the timing if they detect knocking. Without doing some ECU tuning, the timing will always be set to or below (if knocking is present) whatever toyota engineers pre-programmed it to be based on engine and air conditions.

Premium might help keep the timing from retarding under high engine load like heavy acceleration or towing/hill climbing when knocking might occur, but for most daily driving, the engine will use the same timing settings it uses on regular gas.


Wouldn't a higher octane allow the engine to increase its timing and make more power, which means that less fuel is needed to maintain a given speed?

[cleong]

So we should only run the absolute minimum RON recommended and anything above is just a waste of money?

[churp]

No...it depends on how you drive. Lots of flat land and easy driving---87 octane. Lots of hills without slowing down and not creeping up them, and lots of fast starts----you may see a little better mileage with higher octane, but only during those higher load conditions. Each individual driver would have to judge for themselves if it would be a cost benefit....it's a slim one at best, but it may feel like a little more power in those conditions.

[eTiMaGo]

So we should only run the absolute minimum RON recommended and anything above is just a waste of money?

that seems to be the consensus...

I've just looked through all the ECU and ignition related stuff in the repair and technical manuals... my head's spinning now, our humble little car has some pretty advanced systems...

I was trying to find out if the ECU has any kind of learning system, that might try to advance the ignition timing until knock is detected, as this would allow it to run the maximum ignition advance regardless of the fuel used. But I find no evidence of this, but also no evidence of the contrary. From what I gather, the actual spark timing is determined by the crankshaft and camshaft position sensors, and retarded by the knock sensor when required.

What I did find out, though, is that the spark advance can be set in a range from -64 to +63.5 degrees, and the normal value when idling should be between 0 to 14 degrees.

Truthfully, the only way we can know for sure, is to have some device such as the Toyota intelligent tester used by the technicians, to monitor the actual ignition timing while driving with different tanks of fuel, such as 87, 91, 95 octane, and compare the average timing between each tank. Until then, it's really a matter of educated guesswork and subjectivity...

[WRBlue]

No...it depends on how you drive. Lots of flat land and easy driving---87 octane. Lots of hills without slowing down and not creeping up them, and lots of fast starts----you may see a little better mileage with higher octane, but only during those higher load conditions.

And only if your getting knock during thoes times. We drove up to Tahoe a couple months ago in the Yaris. It was slow, we did climb 8000 feet, but there was no knock and we got about 35MPG (higher than our average). Next time we're taking the WRX though ;)

[churp]

And only if your getting knock during thoes times. We drove up to Tahoe a couple months ago in the Yaris. It was slow, we did climb 8000 feet, but there was no knock and we got about 35MPG (higher than our average). Next time we're taking the WRX though ;)

You will not get a knock unless the ECU malfunctions....but it is guaranteed a 10.5 to 1 compression engine without knock sensors and ECU runs like crap on 87 octane. You would be able to get it to run level ground and very mild acceleration with good mileage,but you wouldn't want to drive up a hill. If you retarded the timing enough to be able to climb a hill the gas mileage would suffer big time. The ECU w/ knock sensors are wonderful items!! Premium would only add a little more power/efficiency on the climb IMO...definitely not enough to match the WRX!

[fu_im_from_texas]

... our humble little car has some pretty advanced systems...


+1

You dont get to design dynamic system controls at toyota without being very sharp. Toyota recommends 87 ...

[churp]

+1

You dont get to design dynamic system controls at toyota without being very sharp. Toyota recommends 87 ...

Toyota doesn't recommend 87.....they say: Select Octane Rating 87 or higher (read the owners manual, page 178, or other posts)...in the English language this means 87 is the lowest they allow. And yes they are very sharp.

[fu_im_from_texas]

Toyota doesn't recommend 87.....they say: Select Octane Rating 87 or higher (read the owners manual, page 178, or other posts)...in the English language this means 87 is the lowest they allow. And yes they are very sharp.

churp,
you are right. the "or higher" means that we should all run 110 octane race fuel ... i bet you will get 87 mpg and 200 hp ... your "understanding" of the english language is revolutionizing the yaris...

[eTiMaGo]

ok maybe it should say "87 or higher, within reason" :biggrin:

[YarisTom73]

Well, with all the :bs: I can only draw the conlusion that we should do what we want with our own cars. If you don't like cheap gas, run something higher. If you don't like high octane, run cheap stuff. 'nuff crying about it, just split the difference and run mid-grade as I do :redface:

[fu_im_from_texas]

ok maybe it should say "87 or higher, within reason" :biggrin:

...also the "xx or higher" is the industry standard for recommending fuel. so my lexus gs430 says "93 or higher" which really doesnt make much sence, because 93 is the highest pump gas avaliable in north america... toyota is saying "use 93"

the yaris says "87 or higher" which really doesnt make much sence because you cant get anything lower than 87 in north america

...the industry standard is to recommend the octane then add "or higher" at the end


"....using a higher octane gasoline than your owner's manual recommends offers absolutely no benefit. It won't make your car perform better, go faster, get better mileage or run cleaner. Your best bet: listen to your owner's manual."
http://www.ftc.gov/bcp/conline/pubs/autos/octane.shtm

why do people insist on ignoring empirical and statistical data?

:barf:

[marcus]

i find the yaris timing is right on the border of you being able to use 87 octane. slight change of slopes and temp even with its ecu adjusting..gives you a sluggish feel...89 got better outcome..its could also be just my car.. "Dont you guys notice a whirring sound when you accelerate , try driving beside a wall" i need to know if this is normal. or a slight knockin on the engine?

[eTiMaGo]

...also the "xx or higher" is the industry standard for recommending fuel. so my lexus gs430 says "93 or higher" which really doesnt make much sence, because 93 is the highest pump gas avaliable in north america... toyota is saying "use 93"

the yaris says "87 or higher" which really doesnt make much sence because you cant get anything lower than 87 in north america

...the industry standard is to recommend the octane then add "or higher" at the end


"....using a higher octane gasoline than your owner's manual recommends offers absolutely no benefit. It won't make your car perform better, go faster, get better mileage or run cleaner. Your best bet: listen to your owner's manual."
http://www.ftc.gov/bcp/conline/pubs/autos/octane.shtm

why do people insist on ignoring empirical and statistical data?

:barf:

Hmmm that's quite probable too, to be understood as, 87 is just fine, but don't worry if for some reason you can only get 91, it won't damage the engine.

heheheh too much science studies is just pushing me to experiment, if only I had that toyota intelligent tester or something similar to measure actual spark advance :frown:

Or, we can find a Toyota ECU engineer from Japan to enlighten us? :biggrin:

[eTiMaGo]

i find the yaris timing is right on the border of you being able to use 87 octane. slight change of slopes and temp even with its ecu adjusting..gives you a sluggish feel...89 got better outcome..its could also be just my car.. "Dont you guys notice a whirring sound when you accelerate , try driving beside a wall" i need to know if this is normal. or a slight knockin on the engine?

I wouldn't be knock, I pored through all I could find in the repair and technical manuals, as soon as the knock sensor feels something out of the ordinary, it will retard the spark, so unless there is something wrong with the knock sensor, you should not "feel" knock for over a second.

[jdium]

i find the yaris timing is right on the border of you being able to use 87 octane. slight change of slopes and temp even with its ecu adjusting..gives you a sluggish feel...89 got better outcome..its could also be just my car.. "Dont you guys notice a whirring sound when you accelerate , try driving beside a wall" i need to know if this is normal. or a slight knockin on the engine?

Maybe if feels sluggish because it's only 105 hp going up a hill in hot weather? :wink:

As for the whirring sound, it's probably exhaust noise. As quiet as these cars are, there is still some noise. It dissipates easily normally, but a wall would reflect it back to you...

[marcus]

thanks guys hopefully its nothing...

[hystria]

So we should only run the absolute minimum RON recommended and anything above is just a waste of money?

PROBABLY higher octane/RON will provide better fuel economy with this car... but the difference will be too minimal to be easily measured by just checking a mileage variation. YES, Toyota recommends using higher octane/RON for this engine in order to obtain better mixture burning, resulting in less polluting emanations. Buying 10-15% more expensive 89/91/94 gasoline won't result in 10-15% mileage increasing. Check out the black smut (?) on the exhaust when running on 87 octane, then whip it off and switch to 91 and check again.

[fu_im_from_texas]

PROBABLY higher octane/RON will provide better fuel economy with this car... but the difference will be too minimal to be easily measured by just checking a mileage variation. YES, Toyota recommends using higher octane/RON for this engine in order to obtain better mixture burning, resulting in less polluting emanations. Buying 10-15% more expensive 89/91/94 gasoline won't result in 10-15% mileage increasing. Check out the black smut (?) on the exhaust when running on 87 octane, then whip it off and switch to 91 and check again.

"....using a higher octane gasoline than your owner's manual recommends offers absolutely no benefit. It won't make your car perform better, go faster, get better mileage or run cleaner. Your best bet: listen to your owner's manual."
http://www.ftc.gov/bcp/conline/pubs/autos/octane.shtm

why do people insist on ignoring empirical and statistical data?

[bearda]

This is one of those discussions that just doesn't go away. I've seen the same thing on almost every non-premium fuel car forum I've seen. The signal to noise ratio tends to vary, but you've always got a couple people clinging to numbers and reports, a couple people clinging to their anecdotal evidence, and a couple people clinging to some hope that they can improve performance.

Just to add fuel to the fire, though, I don't think higher octane gas is going to do much of anything for you (nothing good, at least). Higher octane gas doesn't give you higher performance; it just resists pre-detonation. If you're at the point where the ECU is retarding timing due to pinging it'll keep you from losing performance. Unless the ECU is really designed for performance it isn't going to keep advancing the timing on it's own unless it's already retarded the timing (There are some that do do this. The WRX actually starts with a very conservative timing advance then ramps it up until it knocks, then pulls it back a little).

Higher octane gas CAN give you better mileage if the car can take advantage of it. Octane rating is basically a measurement of how long it takes fuel to burn. If the fuel burns longer you don't need to burn quite as much of it in the optimal case. You've got to get the ECU to realize that, though. If the ECU keeps the same ignition timing/AFR/whatever you're not going to see any benefit.

One thing I have seen with higher-octane fuel on a car factory-tuned for 87 is starting delay. From what I can tell (and this is coming almost entirely out of my ass, as this goes right past my league) since higher octane gas is more resistant to predetonation sometimes it's also a little too resistant to initial detonation. You try to start the car and the ECU finds the gas a little harder to light than it thought. Not a big deal at all, but at times an indicator that lower octane gas can actually run better than high-octane.

If you're looking for the best gas for your car just buy GOOD gas, not higher-octane gas. Go with a station that stocks gas with additives and detergents in it's 87. Chevron is a great example of this; they put their Techron additive in all the gas they sell. Once again, it's isn't going to add any more performance or gas mileage the car didn't have at one point. Maybe it'll keep it running a little cleaner, though, and it's my personal opinion that you're more likely to see a benefit from that than running high-octane gas.

[Kioshi]

...also the "xx or higher" is the industry standard for recommending fuel. so my lexus gs430 says "93 or higher" which really doesnt make much sence, because 93 is the highest pump gas avaliable in north america... toyota is saying "use 93"

the yaris says "87 or higher" which really doesnt make much sence because you cant get anything lower than 87 in north america

...the industry standard is to recommend the octane then add "or higher" at the end


They say some number and higher because say if you are driving in a foreign country....than something higher than whatever number they tell you can be used. But who would spend the money to be driving a U.S. car in Europe or Africa anyway ~

Like Tom said, just use mid grade. If its used car use cheap stuff. If its a new car in your first hands, use mid grade. If its hp is 173+ use premium~

[cm07yaris]

This topic always comes up on every forum that has to do with something that uses gas. It also turns into a huge debate taking up several pages and ending with the same result. The same goes for the big debate between using synthetic or natural oil.

[hystria]

"....using a higher octane gasoline than your owner's manual recommends offers absolutely no benefit.

TRUE. As per Yaris manual, it recommends 87 or higher. Why "or higher" ? Ever wonder why Toyota recommends wasting your money ? With NO REASON ? Is Toyota in business with Shell ? Well, if not, there should be a reason, unless there are places on Earth that sell only 89 or higher octane gasoline... don't think so...

Engines are optimized to run with a precise level of octane. If an engine requires 87 and the owner put 89 or higher, there will be absolutely no benefit for the engine. On the other hand, if and engine is optimized to run with 89 and the owner uses 87, the engine will not run at 100% performance. It will knock more or little because the mixture ignites before the optimum moment during compression, thus leading to hot points on the piston/ring surface. Because the mixture ignites before the moment when the engine compression is optimal, it produces less overall performance. But not by much, one will not be able to feel any difference.

To resume... if using 87 the engine starts knocking, try changing the brand... the Yaris engine should not be knocking to an audible/damageable level while using good quality 87 octane gasoline.

[WRBlue]

Like Tom said, just use mid grade. If its used car use cheap stuff. If its a new car in your first hands, use mid grade. If its hp is 173+ use premium~

That makes no sence...

If anything, an older car needs higher grade gas because of bad maintance, wrong plugs, carbon buildups in the combustion chamber, etc. But, if a car is maintaned, there is no reason what so ever to use anything but 87 octane. I have been to gas stations that don't sell less than 89, and I've been to some that sell 86...

There are a great many cars that make more than 170hp that only use regular. For example: My last truck was a V6 S10 that made 200-ish, and ran best on 86. The Jeep I traded in for the WRX made 235hp on 87.

[Jerkratt]

ok there is stuff higher then 93 in north america its ether 94 or 95 from shell or sunoco

[Kaotic Lazagna]

wow, i can't stand to read this thread anymore, and it's my own thread. lol...

[davembfan]

I usually get 87, but i got 89 once and it was about the same with mpg. since I have had my car i've always used shell gas, don't plan on using another brand. I've always been weird with gas and my cars, always fill up the same place, usually the same pump. Unless of course im on a trip, but then ill still use shell.

[Edd]

Using higher octane than recommended will NOT make the engine knock*. It will make it less likely to knock. Higher octane = more stable and less likely to prematurely combust.
Members in this thread are correct in saying that you will most likely have no benefit from increasing the octane rating on the fuel (unless your car knocks at the recommended amount).
The top fuels (98 RON) are there to replace leaded petrol. Back in the day, lead was THE way to boost octane. Now we can achieve higher octane ratings without it, there is no need to burn lead in old cars.

*Heh, I just read the last couple of pages and I don't think anyone said it would. Nevermind then. :biggrin:

[fu_im_from_texas]

wow, i can't stand to read this thread anymore, and it's my own thread. lol...

+1 ...last post from me for this thread... i promise...

[marcus]

so whats the verdict on this topic?? is premium 89 octane gives out better mileage or is it regular gas 87 octane.. what is it?? :iono:

[Pavel Olavich]

Using higher octane than recommended will NOT make the engine knock*. It will make it less likely to knock. Higher octane = more stable and less likely to prematurely combust.
Members in this thread are correct in saying that you will most likely have no benefit from increasing the octane rating on the fuel (unless your car knocks at the recommended amount).
The top fuels (98 RON) are there to replace leaded petrol. Back in the day, lead was THE way to boost octane. Now we can achieve higher octane ratings without it, there is no need to burn lead in old cars.

*Heh, I just read the last couple of pages and I don't think anyone said it would. Nevermind then. :biggrin:

Edd, you make very good points. I just want to add that high octane is not just for old engines that required lead. In fact there are many very old cars that didn't need high octane, yet they did require lead. Even some 2008 models require high octane, for it's slower combustion properties; often these engines are large in displacement, and/or provide very high compression, and/or they utilize a turbo that requires a delayed burn inside the cylinder.

Reality Check Folks: Our small 1.5L low compression, non-turbo, low, low performance Yaris cars are the LAST car to get any benefit from high octane gas.

Lets get real here folks....most of the "benefits" many think they get is all in their heads....anyone hear of the Placebo effect?

Funny how age comes into play on this issue. My two teenaged daughters, both drivers, have several male friends in their age group, that all drive late model Japanese cars that DON'T require high octane, yet they ALL only use high octane gas, as they all have this dillusion of premium giving more "power" and more "speed".

Teenagers! Youth! LOL

Save your money, and be happy.

[Pavel Olavich]

TRUE. As per Yaris manual, it recommends 87 or higher. Why "or higher" ? Ever wonder why Toyota recommends wasting your money ? With NO REASON ? Is Toyota in business with Shell ? Well, if not, there should be a reason, unless there are places on Earth that sell only 89 or higher octane gasoline... don't think so...

Engines are optimized to run with a precise level of octane. If an engine requires 87 and the owner put 89 or higher, there will be absolutely no benefit for the engine. On the other hand, if and engine is optimized to run with 89 and the owner uses 87, the engine will not run at 100% performance. It will knock more or little because the mixture ignites before the optimum moment during compression, thus leading to hot points on the piston/ring surface. Because the mixture ignites before the moment when the engine compression is optimal, it produces less overall performance. But not by much, one will not be able to feel any difference.

To resume... if using 87 the engine starts knocking, try changing the brand... the Yaris engine should not be knocking to an audible/damageable level while using good quality 87 octane gasoline.

The "or higher" phrase only means that if 87 is not available, then using a higher octane is not going to damage your engine.

Don't be so quick to read more into the words, then what is literally meant.

Also, to suggest as a remedy, to use higher octane than called for in the manual, a way to remove knocking is plain wrong. It would be far better to take the car in and determine why it is knocking at the required octane, and to remedy the problem. Going up in octane is a band-aide that only masks a real problem.

[eTiMaGo]

Since this topic is back alive, I should mention that I tried a higher octane in my last two tanks, with no noticeable increase in mileage and/or performance. Mind you, it was an ethanol mix, so it may have had a part to play. You won't blow up your engine with higher octane, but whatever benefits probably do not outweigh the extra cost.

[Pavel Olavich]

i find the yaris timing is right on the border of you being able to use 87 octane. slight change of slopes and temp even with its ecu adjusting..gives you a sluggish feel...89 got better outcome..its could also be just my car.. "Dont you guys notice a whirring sound when you accelerate , try driving beside a wall" i need to know if this is normal. or a slight knockin on the engine?


I know the sound you're talking about....my old '97 Camry did the same...that sound is NOT pinging...it is just the fuel injectors doing their thing....yea, my Yaris does the same thing when I drive near a wall....again, not pinging, just valve and injector noise....no worries.

[marcus]

I know the sound you're talking about....my old '97 Camry did the same...that sound is NOT pinging...it is just the fuel injectors doing their thing....yea, my Yaris does the same thing when I drive near a wall....again, not pinging, just valve and injector noise....no worries.

thanks pavel ur the first to mention the fuel injectors..atleast im not the only one that notices the noiise during acceleration..:thumbup:

[Speedz]

so whats the verdict on this topic?? is premium 89 octane gives out better mileage or is it regular gas 87 octane.. what is it?? :iono:
There isnt any noticeable difference in performance or economy when using 87 or 100... I tried all of them... nah zilch nothing...

Only thing is your money been spent... mine you in Australia Shell's 100 octane was about $1.45/L vs $1.06/L for the 91 octane...

[aca72]

My take:
Got a cheap car? Buy cheap gas.
Use "87 or higher" (per Yaris manual).
Maintain your car diligently and drive sensibly.

[Black Yaris]

everytime I use more premium fuel I get better fuel econimy..... the econ rating on the sticker from the factory were tested with 89 octane.... I use 89 or 91

[Kaotic Lazagna]

brought back from the dead again. lol...i have't used premium every since the last time this thread was resurrected.

[Black Yaris]

I am half temped to kill it.... I think we have all repeated our selves 3 times in this thead argueing the same thing back and forth, getting nowear... everyone is going to believe what they are going to believe... and not one is going to change there minds

[Kaotic Lazagna]

yes, please kill my thread. let someone else start a war. i did it with this thread and my synthetic oil thread.

[Black Yaris]

dead... too much bickering...