I had a 1998 Cadillac DeVille. It has 141,000 miles on it. It has been a good car. I get 25-26MPG on trips. I commute to Washington, DC, about 50 miles each way. I have an apartment in town so I don't drive every day. Somedays I'll take a bus or train. The trip is about 40 miles on interstate highways and maybe 10 miles in heavy traffic. I get about 20-21 MPG on these trips. I just filled the tank on the 400H last night so I will get a better handle on the true MPG.