Thank you (I think I double posted this question in another thread). I'm not sure what the purpose of you using 91 without changing the tune was but those calculations were exactly what I was looking for. What i'm trying to find out the cost per mile and which tune is more cost effective as you put it. +/- a few HP is not as important as +/- mpg with fuel being over $3/gal.
Can a level 3 tune be done with 87 octane? What differences would be the result versus a level 3 tune iwith 91?
