[BleedDodge]

Yeah, whatever gave you that calculation for the 1 mpg drop is probably just something that had to do with your driving habits. You might have idled the truck a little bit more one day or drove a little harder another day or something, 1 mpg is just no cause for concern because it's such a small difference in mileage that it can't be traced to what caused it...

I know when I had the big pipes and Dynomax mufflers put on my truck, I found myself running harder and faster, just to hear the truck bark. I'd rev it higher and stuff like that. I don't know what your driving habits are like, but maybe you're the same way. I wouldn't be worried about a 1 mpg drop, unless it was all highway driving at a constant speed, then I would maybe take a second look at things...