I have a 97 audi a4 1.8L turbo AWD and I get about 8MPG city and highway driving, my tire pressures are up, right tire size, recent oil change. it has about 150000 miles on it, the transmission recently went into limp mode (i will make an other thread) but ever since i got the car it was reading 8-10 MPG. is there anything i should go over or check maybe common problems ? any help is appreciated.