Try the tow tune for giggles...you will love the shifting. I don't use my custom tune anymore.

 

20-22mpg? Must be nice! I went from 13.9 stock to 14.6 in tow tune. I would be happy with 15!

 

I am betting the 22 was a fluke personally, but I'll take it. 20 seems like where it'll settle more realistically, since I was doing 18-19 before (highway).

jkeaton, does the tow tune get about the same mileage as the 91 performance? I didn't buy the thing for mileage, but not sure I will be happy if I start dropping the mileage number.

 

I actually saw an increase in my mileage, from mid 15's to almost 17.

 

22 isnt a fluke, I have mine documented getting 21, overall averaging 16 only because I hit a 12 mpg once in the winter months from hauling my trailer (while flogging the truck) and allowing the truck to idle probably 15 minutes every time it started (or it could have been an error in my numbers filling up too)... it was cold you know!

 

Allow for shrinkage in the cold....that's what Bobby would say.