I have 33 x 12.5 w/ 4.88 and with lift kit & body lift. Acceleration is like stock, and gas mileage for me is about 20mpg or over if I am going 55-60mph. If I am doing 65-70mpg it drops to around 17-18mpg. It does pretty good around town to, not sure on any numbers but does good.
Now if I start driving like a crazy man with a lead foot than the gas milage starts to suck.