I just bought the 550i after looking around for a few months. I wanted the performance but I was concerned about the fuel economy. If you can believe the gauge on the car, I am getting 28.6 MPG on the highway. It is only rated at 25, so that is excellent. When I fill it up again I will verify that number. This car is a pleasure to drive. It's quick, quiet, and comfortable. Sport package not necessary. Automatic is best for most. There is a 1300 dollar gas guzzler tax on the stick shift.