Higher octane fuel

[frailer]

Hi, I have just taken delivery of a 5 door hatch, location Eastern Australia. My main problem is that I may need to be prised out of the driver's seat sometime. I love the damn thing!
The VVTi obviously smooths out a lot of things, but feel that stating 91 RON as the fuel to use doesn't make sense to me. Marketing silliness, IMO.

Given that the compression ratio is 10.5:1; I reckon on my 1st fill, (sometime in 2010...LOL :laugh:), I may switch to 95 RON. I think that I may get increased mpg, more zip/smoother...though few complaints there; and also be kinder to the motor.

It's a 1.3 litre donk.

Would welcome anyone's experiences.


...Oops! Just found some threads...Mods feel free to flick my thread. Thanks...

[Tamago]

nope, won't see improvements

if toyota had bothered to make the ECU a little more agressive you would..


but ..

you won't..

don't waste your money ;)

[frailer]

Thanks guys. I understand that RON number calculations differ around the world. Here in Aust. we have 91, 95, 98. After reading here:

http://www.yarisworld.com/forums/showthread.php?t=3233

...and your comments; I'm going to stick to 91, I think. I guess Toyata have been smart enough to design it around the lower octane fuel, despite the slightly higher comp. ratio.

Appreciate your input.

[BluYrs]

95 is recommended for my 1,0, however I use 98. Why? The engine runs a lot smoother (less vibration), MPG and power gains are negligible (if any), but it just feels a lot better. The nonexistent price difference around here (1,5%) makes this a no-brainer for me.

[Yar Is Word]

I used premium in an ECHO for 5 years and always from name brands, not the cheap gas. The car simply ran smoother, it had more power, and got better mpg (about 2 per gallon). The increase in mpg did not cover the increase in cost but the peace of mind was worth it.
In the Yaris the first two tanks were regular. I felt the acceleration could improve. Since premium was put in a difference has been noticed. The car is relatively new so I don't have any long term mpg improvement data.
I have read a couple studies and many opinions such as the ones above stating that it's a waste but that has not been my experience.
A simple test would be to run premium for a few tanks and see if you notice any improvements.

[06vitzRS]

From what i learned in my technical training, going with a higher octane will do nothing but drain your wallet faster. Just put in what the owners manual states. To each there own, if you want to put in a higher octane it's your choice.

[YarisSedan]

Higher octane will lead to excessive carbon buildup

[jambo101]

I used premium in an ECHO for 5 years and always from name brands, not the cheap gas. The car simply ran smoother, it had more power, and got better mpg (about 2 per gallon). The increase in mpg did not cover the increase in cost but the peace of mind was worth it.
In the Yaris the first two tanks were regular. I felt the acceleration could improve. Since premium was put in a difference has been noticed. The car is relatively new so I don't have any long term mpg improvement data.
I have read a couple studies and many opinions such as the ones above stating that it's a waste but that has not been my experience.
A simple test would be to run premium for a few tanks and see if you notice any improvements.
This attitude is what the oil companies are after,Someone who is totally misinformed and think the higher octane gasoline somehow gives more power,better gas mileage and somehow works better than what the engineers who designed the engine recommend:confused:I think this attitude has been perpetrated by all the fancy names they call the higher octane gasolines relegating the lower octane gas as an inferior alternative to Premium,Gold Ultra,Super etc.When in actuality the only difference between 87 octane and 93 octane is detonation parameters not the quality of the gas.The owners manual in all Yaris and Echo's call for the lower octane rating of the usual three choices of gasoline.If there was any merit to the higher octane = more power and better mpg dont you think the car companies/engineers would be the first to recommend the higher octane gasoline.
The logic of buying an inexpensive automobile who's forte is fuel economy then putting a more expensive higher than recommended octane gas in it escapes me.

[MUSKOKA800]

Save your money and follow whatever your owners manual specifies. That's what it's designed to use most efficiently.

[Tamago]

lol @ the answer repeated over and over again, even after the OP has acknowledged..

[BLAZINBLUEVITZ]

BOOO, i guess i waste my money.........

[YarisPR]

I use 91 always!!! (unless unavailable)
Why?
Here (in P.R.) Regular gas (specially from generic gas stations) = POS!!!
Premium (91) gas = maybe regular gas up there in the states. My prove? VW 1973 Tranporter (91+ only). Cheap 91 in this VW = bad combustion, rattling, slow response, it even stays a few seconds rattling after its turned off. So if the cheap/generic 91 sucks. I don't even want to know what the 89 (regular) does. So thats why I use 91.

[jkuchta]

The octane mention in the owner's manual is a MINIMUM requirement, not a recommended octane rating.

I see higher ignition advance under all conditions (via scangauge) with 91 than I do with regular.

[YarisSedan]

Maybe you guys who say 91 is better is because you have so much carbon buildup in the engine that its changed the compression ratio so thus it does run slightly better with higher octane now =) Carbon on top of the pistons reduces the volume of the combustion chamber

[frailer]

I don't mind the extra posts. It's all a mixture of info and opinion. Just gotta use your head to sift through it. :smile:

I'll keep an open mind, but continue with 91, (base fuel here).

Thanks for the replies.

[1NZYaris1]

nope, won't see improvements

if toyota had bothered to make the ECU a little more agressive you would..


but ..

you won't..

don't waste your money ;)

Yep Save your money and put it towards Mod's ,
like air intake , axle back exhaust , NST pullies will give you an amazing boost, and once you've done that you will need a short shifter to keep up:laugh::laugh::laugh:

[1stToyota]

Yep Save your money and put it towards Mod's ,
like air intake , axle back exhaust , NST pullies will give you an amazing boost, and once you've done that you will need a short shifter to keep up:laugh::laugh::laugh:

Yes, and after those mods and a performance tune then that'd be the time to actually make use of the higher octane.

[Tamago]

Yep Save your money and put it towards Mod's ,
like air intake , axle back exhaust , NST pullies will give you an amazing boost, and once you've done that you will need a short shifter to keep up:laugh::laugh::laugh:

don't forget to buy a neck brace so you don't injure anything with your newfound rocket-like acceleration.

[500snakz]

Plain and simple...the yaris is designed to run on 87 octane gas(REG) and running 93(premium) yes we have 93 here, could actually cause poor performance and may actually damage your motor. Read your owners manual and use the recomended fuel type. MORE is not allways better. I would just stick to the book and make sure the dealer dont have an excuse to void my waranty.

[BLAZINBLUEVITZ]

Plain and simple...the yaris is designed to run on 87 octane gas(REG) and running 93(premium) yes we have 93 here, could actually cause poor performance and may actually damage your motor. Read your owners manual and use the recomended fuel type. MORE is not allways better. I would just stick to the book and make sure the dealer dont have an excuse to void my waranty.

yeah my dealer just got that new fuel grade machine where they test your gas to see if your running what the factory says.....

[jkuchta]

The octane specified in the owner's manual is a MINIMUM requirement, not a recommended octane rating. Your warrenty will NOT be voided by running higher test fuel.

I see higher ignition advance under all conditions (via scangauge) with 91 than I do with regular, which tells me that the car is actually taking advantage of the higher octane. The people that mention their warranties being voided on this forum would do well to learn about octane ratings and meanings.

[Tamago]

The octane specified in the owner's manual is a MINIMUM requirement, not a recommended octane rating. Your warrenty will NOT be voided by running higher test fuel.

I see higher ignition advance under all conditions (via scangauge) with 91 than I do with regular, which tells me that the car is actually taking advantage of the higher octane. The people that mention their warranties being voided on this forum would do well to learn about octane ratings and meanings.

and does your scangauge pat you on the back and say 'omg bro, check out your newly found power!!' ?

[Castaway]

Wikipedia: The octane rating is a measure of the resistance of gasoline and other fuels to detonation (engine knocking) in spark-ignition internal combustion engines. High-performance engines typically have higher compression ratios and are therefore more prone to detonation, so they require higher octane fuel. A lower-performance engine will not generally perform better with high-octane fuel, since the compression ratio is fixed by the engine design.

[ChinoCharles]

I'm going to go ahead and close this one up guys. I think the OP's question was answered sufficiently. Another job well done, YWers.