^^^^Once you lift a truck and put bigger tires on you can't rely on the instant MPG gauge in your trucks DIC. It's tuned to factory equipment, and not that accurate in the first place. If AZ were to get a tune and correct the tire size, his instant MPG would improve but still not be completely accurate. Best bet is to hand calculate the MPG over a few tanks and find out what your actual MPG is. Winter blend gas is also to blame here, there are additive put in it to stop it from gelling in the cold…
My truck has 275/70/18's with a 2" level, it get's driven in the city a lot lately and says it's getting about 10MPG, but after hand calculating it, I'm actually getting 13-14MPG, which isn't bad for the amount of city driving I'm doing, with the Christmas holiday traffic, and with the winter blend gas that's in the tank… I can't wait to go on vacation in the new year and stretch the trucks legs, even with the winter blend I think it should get close to 20-22MPG… Before, when the truck was stock, on long trips with premium summer grade gas, I was getting 28+mpg on long trips. I knew the bigger tires were going to take a hit out of the fuel mileage, but the stock tires and clearance weren't going to get me to my fishing camp…