Whats the best tune to run for everyday driving? all we have available here where i live is 85.5 which i never use and 91 octane which i do use. i just got my tuner and i don't want to get things wrong and mess up my truck.
I've never heard of 85.5 octane fuel....wtf is that used for? lol. Every car pretty much is designed for 87 octane, and some higher.
Anyway, if you have 91 in your area, you could run a 91 tune, and that would be good performance and mpg for the street. I usually run a 93 tune as 93 is available just about everywhere in my area. Lately I've been running an 87 tune to save ~thirty or forty cents a gallon though. MPG doesn't really change between the 87 and 93 tune from what I can tell, but power is better on the 93 tune for sure.
Another option(though a PITA) is to mix the 91 and 85.5 octanes to get an 87 octane and use an 87 octane tune.