So i just did my timing belt, valve cover gasket, new tires(which are bigger), and have had a significant drop in fuel mileage and power/acceleration. Now, i understand and expected some loss of fuel mileage and power from the larger tires, but it had a very difficult time getting up the hills on i65 going to atlanta. The fuel mileage dropped from 28 average to about 21-22. It had to down**** a lot to keep a steady speed going up the hills. Any input is appreciated.