I bought a set of factory R/T wheels (18 inch) and replaced the 17's on my2006 Charger SE. After the change the gas mileage has gone down. Does anyone know if I should take it to the dealer to re-program the computer system? Should changing to the larger wheels make a big difference in the mileage?

Interesting. How are you calculating the milage?

If you using the car's calculated milage and didn't adjust the tire size withing the Power Control Module (PCM) then that's going to be off.The difference isprobably marginal but it's not accurate. Either pick-up a tuner that allows you to change the tire size or have the dealership do that for you.

Thanks MangoInTX for the info. I have a Dodge dealership about 15 minutes away. Going to Pensacola next week and I'll have it adjusted when I return.