Savannah Dan
Member
What I found out about 87, 89, and 91 octane fuel with the factory tune:
I can't find my notes, so I don't have the exact figures. I got about 1 more MPG with 89 than I did with 87. I got about 1 more MPG with 91 than I did with 89. After doing the math, I found out that the cost to run 91 was about the same as running 87 or 89. I was very surprised.
I tried the same with non ethanol gas, hoping to get even MPG, but the results were about the same.
Edited to add post from June 2018:
I can't find my notes, so I don't have the exact figures. I got about 1 more MPG with 89 than I did with 87. I got about 1 more MPG with 91 than I did with 89. After doing the math, I found out that the cost to run 91 was about the same as running 87 or 89. I was very surprised.
I tried the same with non ethanol gas, hoping to get even MPG, but the results were about the same.
Edited to add post from June 2018:
I ran tanks of 87, 89, and 93 in my 2017 to check the mileage. I don't have the numbers in front of me, but the higher the octane, the better the MPG. Ran a bit stronger too. I calculated the cost per mile for each. 89 was about $.15 a mile and 93 was about $.17 a mile to drive.
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