Premium Gas

[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]

Originally Posted by 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.

cool, cool, this premium stuff is weird.

[Pavel Olavich]

Originally Posted by Black Yaris

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]

Originally Posted by marcus

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]

Originally Posted by 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.

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]

Originally Posted by 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.

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]

Originally Posted by Pavel Olavich

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]

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!!

Carry on.

[Black Yaris]

Originally Posted by churp

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!!

Carry on.

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

[churp]

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

[Black Yaris]

Originally Posted by churp

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

What? Please edit, that does not make sense

[acrbill]

Originally Posted by Black Yaris

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

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]

Originally Posted by Black Yaris

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.