I own a CPO'd '08 328xiT (E91) and have been wondering about the poor gas mileage I've been getting since buying the car in May of 2010. I bought the car with 13.5K on the clock. I commute about 55 miles a day over a route that is divided somewhat equally between highway and local streets. On the weekends, I try to use my other car as much as possible to keep the usage down but I still have to take my car out on occasion. I've taken one long trip with it and I'm not in the habit of driving like an animal. Since buying the car, I've never seen 21 mpg on the computer. Usually, the gas mileage hovers between 19 and 20.5. If I calculate it tank by tank the mileage is about 0.5 mpg better than the computer's result. I've tried all available grades of gas at different gasoline vendors. So, does it take that much more power to turn the AWD plumbing? The car weighs 100kg more than a RWD wagon so that's similar to driving around with another adult male in the car and I realize that could account for some of the loss of mpg. I keep seeing dashboard shots and reading articles in Roundel of BWM's with a lot more hp than I have averaging over 25 mpg. I also have a friend with an E36 M3 (his only car) and he claims a 26 mpg average. Is there some possible issue with my car or is this kind of normal and I should stop worrying?