I was under the impression that these tunes were bumping up fuel efficiency as well as hp. is that the case? if so what are kind of numbers are we talking here? average mileage for untuned cars seems to be about 17mpg. at 2.50 a gallon this is something i am very mindful of.

 

I get 22.5 on highway at 80 mph wiht 4:10 gears.

-Bryan

 

My combined driving (lots of city) is now 18.5 after my Diablo 91 octane tune. Before my tune I was getting 18.0 combined. It's not much but at least it's in the right direction.

 

im combined 22 mpg, diablo premium tune

since i sold the predator, im at 18.2 average


same driving style

only difference, no tune, and 87 octane rather than 93 in the tank