I have 5000 miles on my 4.8i. I drive 25 miles each way to work on CT rolling hills and backroads and back and forth to NYC on occasion. My life of car mileage is 14.8 mpg. When I concentrate on driving for mpg, I can get 16.8 mpg. The car is so smooth on the highway, I can't drive less 80 mph, so I don't count my highway mpg as being realistic!