I just installed a bullydog powerpup and an AFE cold air system on my truck and am running the power pup on the tow setting, my instant mile per gallon says I am only getting 19 mpg , when before my truck was getting 22mpg when it was bone stock. is it just my instant mpg is off because of the program??? my truck is an 04.5 2500 5.9 HO

 

Never pay attention to the lie o meter in your truck. The only way to get the correct mpg is to hand calculate.

 

You could be playing harder with the go pedal and not really know you are doing it. Wait for some of the shine to wear off and do a hand calc on a couple of tanks. That said not all mods increase fuel mileage.