3 tanks of regular / 3 tanks of premium

09 4x4 DC Sport SB - 3 tanks of regular / 3 tanks of premium

NO NOTICABLE POWER INCREASE... People on the board have been reporting their butt dynos registering more power, but that is NOT my observation.

Premium average mpg = 18.8
Regular average mpg = 18.4

Premium here is 20 cents more per gallon. I usually put in about 17 gallons, so I'm using 17 gallons for my math...

Premium gets me 319.6 miles from 17 gallons of gas
Regular gets me 312.8 miles from 17 gallons of gas
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I get 6.8 miles farther with 17 gallons of premium


17 gallons * $3.79 (Premium) = $64.43
17 gallons * $3.59 (Regular) = $61.03
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= $3.40 more per fill up for premium


Some people have been posting that it pays to use the premium for mpg, but my numbers are telling me otherwise. I paid $3.40 more to go 6.8 miles farther.

How does this compare to your findings?

 

Haven't did a test. I just know that I'll just stick with 87 not worth it IMO for less than 1mpg extra. I spent the last 2 years putting 93 in my Impala SS which actually recommended that fuel. Any performance increase if it existed would be neglible anyway.

 

Forget about MPG,, doesn't 91 burn cleaner?

 

X2...

 

I can accept the cleaner burning argument, but there are a lot of guys claiming a good mpg gain, and "noticeable" power gains...

 

Here are some comments from one of the recent posts...
http://www.tacomaworld.com/forum/2nd-gen-tacomas/26972-better-gas-mileage-premium.html

Yes, I was getting about 18 mpg with 87 octane, and switching to 93 octane gave me just over 21 mpg.


ya same thing here, prem gets me a heck of a lot more kms

I have tested this, and found, on average, about 2 mpg. better with 91 vs. 87.

When I calced out the price vs. mpg., the higher octain was about $2.00 to $4.00 a fill up less, so its cost affective.

Ive noticed that I get better MPG with premium

After about 3 months of unofficial testing I get about 18.5 mpg on 89 octane and 20.5 on 91 octane

I run premium with octane booster and get about 21 around town

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There are a lot of claims of power gains too, but just doesn't make sense, and I can't feel a gain...

 

i ran 91 when i went to the beach, it did seem to run a little better but mpg didnt change. 91 is about 18 cents more than regular here so they can kiss it im running 87

 

The Sam's Club here keeps their premium 93 octane prices just around 7 cents a gallon more than regular 87 octane and its ethanol free, they don't sell a middle grade.

For a little over a buck more a fill up its worth it.

Also I'd probably reset the ECU between grade changes if I was gonna try to come to a real conclusion, your test really doesn't prove much of anything. Just putting in a higher octane isn't going to necessarily change how the power feels right off the bat either, the computer has to learn and adjust and that can take hundreds of miles by which time your butt dyno isn't gonna realize much.

Which leads to another thing, some gas stations don't put ethanol in their premium gas but do put it in their regular so that can lead to more of a difference.

I've read a few studies that reported 10% ethanol reduces your milage around 7% so that alone is probably worth it.

 

Based on Toyota's own ratings, premium does provide a power bump (mainly in the torque) but whether it is noticeable with a "butt dyno" is completely subjective. The increase in torque from 87 to 91 is roughly 5%, the increase in hp is negligible IMHO.

I run 91 just because I like to have the most power possible (without other mods of course) and because I think my truck runs smoother on it (another virtually impossible thing to measure). To each his own.

Edit: One other thing to consider is that I read that the computer takes at least a couple of tanks to get accustomed to the different fuel type and adjust its operating parameters. I wonder if a longer term test would give more useful feedback than only a few tanks. It would also be interesting to do towing with both fuel types, cold weather operation, etc. There are loads of variables that may be hard to capture with such a short comparison.

 

My problem with this is that I believe in 2005 when the engine for the v6 tacoma was rated at higher hp and torque than it is now, it also called for 91 octane.

That changed the following year and the advertised HP went down aswell.

I know the early reviews for the tacoma when the second gen was coming out said that toyota recommended premium gasoline and a bunch of people said wtf.

 

how fast do you people drive? here in kc gas at 87 octane is 2.27 a ga.

i fill up when the light is on and its around $34 a tank... i can go past 350 miles before the light comes on.. depending on how much city driving i do. but 90% i can go past 350 miles before the light comes on.

and ur just wasting ur money by using anything past 87 in ur truck. higher octance does nothing for our motors.

 

I believe in 2007 they re-mapped the engine to run on 87 Octane at the expense of some horsepower. I don't know if you regain that horsepower in the later 4.0 engine by running high octane. I've tried 89 octane in my 2.7 and there was no increase in power or mileage, just the gas bill.

 

You have some expensive gas. It's about $1.00/gallon cheaper here in northern IL.

 

You sure it was remapped? I was under the impression the 2006-2008 models were exactly the same with all parts interchangable, other than two new colors in 2007.

The manual in my 2009 says to use "87 octane or higher" probably 20 times and never says just "87 octane" and in one part it says "or higher for optimal performance".

I don't think with these engines you can just spout out that it was designed for 87 octane because of the changes its gone through when it wasn't originally designed for 87 and with the sophistication of the ecu as it learns and compensates.


Also once again, ethanol hurts mileage. Often premium has no ethanol, Shell V-power for example has no ethanol. This alone can help power and mileage.

 

thats what ive heard that its a myth that youll get better gas mileage with premium. the higher octane just reduces engine knock. it burns the same so that means same gas mileage.

 

Maybe they didn't re-map the ECU and just changed the recommendation from 92 octane to 87 or higher. Newer engines that require high octane can usually run fine on 87 at an expense of power. Maybe someone with an 05 or 06 can chime in and check thier owner's manual and see what it requires.

 

Reg = ticking, prem=no ticking... but thats just me.

 

Yea, I know my WRX would run fine on 87 but it called for premium, though you could tell there was some torque loss when you were taking off from a stop and had to gas it a hair more than usual. My dirtbike is the same way.

 

The US as a whole will use approx 137,970,000,000 gallons of gas this year (da gubment estimates we use 378 million gallons a day) and yet most of us (myself included) really have no idea how to most effectively use different grades in our engines.

Man we are whores.