Fuel Economy

[BailOut]

I've done that. 89 Octane = a loss of 5% MPG, 93 Octane = a 9% loss.

I tried 2 tanks in a row of each to get a more accurate test (and the low numbers hurt my running tank average). Without a doubt I consistently get the highest MPG with 87 Octane.

Aside from my much calmer driving style two other things that may make a difference for me are that we're always on 10% Ethanol here and I'm at a higher altitude than most folks (my home is at 4,500ft., my office is a 6,350ft., and I traverse an 8,900ft. summit to get there).

[ern-diz]

Originally Posted by BailOut

I've done that. 89 Octane = a loss of 5% MPG, 93 Octane = a 9% loss.

I tried 2 tanks in a row of each to get a more accurate test (and the low numbers hurt my running tank average). Without a doubt I consistently get the highest MPG with 87 Octane.

Aside from my much calmer driving style two other things that may make a difference for me are that we're always on 10% Ethanol here and I'm at a higher altitude than most folks (my home is at 4,500ft., my office is a 6,350ft., and I traverse an 8,900ft. summit to get there).

facinating...i just filled up with my first tank of 91...have been running 89 and it appears as though to start i'm getting a bit better mpg with the 91 than i have with the few tanks of 89...as far as conditions go, i'm in socal and its been warm (besides today lol)...trying to figure out what would be the best octane to run for engine life vs. FE...87, 89 or 91...

[voodoo22]

Originally Posted by BailOut

I've done that. 89 Octane = a loss of 5% MPG, 93 Octane = a 9% loss.

I tried 2 tanks in a row of each to get a more accurate test (and the low numbers hurt my running tank average). Without a doubt I consistently get the highest MPG with 87 Octane.

Aside from my much calmer driving style two other things that may make a difference for me are that we're always on 10% Ethanol here and I'm at a higher altitude than most folks (my home is at 4,500ft., my office is a 6,350ft., and I traverse an 8,900ft. summit to get there).

Do you have Shell gas around there which put 0% ethanol in their V-power? I wonder how that would result. I can't see you gaining over 9% based on no ethanol. I only use regular and can't justify spening over 10% more for gas when the car doesn't need it. After years of buying premium, spending less than $30 on gas at the end of the week is something I don't want to give up

[BailOut]

Originally Posted by voodoo22

Do you have Shell gas around there which put 0% ethanol in their V-power? I wonder how that would result. I can't see you gaining over 9% based on no ethanol. I only use regular and can't justify spening over 10% more for gas when the car doesn't need it. After years of buying premium, spending less than $30 on gas at the end of the week is something I don't want to give up

I only use Shell gas and E10 is a mandate. Regardless of the Octane level, if you buy it in Nevada or California it's 10% Ethanol. In the cold months it gets worse as our Winter fuel - by mandate - is E10 RFG (reformulated gasoline).

This helps the lead-footers produce much less emissions, which is a good thing, but by proxy it robs the proper drivers of lots of mileage.