I agree about the conservative mileage ratings. I just bought a 2010 Toyota Corolla, so far I am at 37 MPG and that is combined city and highway mileage. The official rating is 28 city and 34 highway.

I do however own 2 other vehicles, both 2004 models and the mileage rating is right at the real mileage. A Chevy that gets 21 MPG highway and a Land Rover that gets around 16 MPG. So far the Corolla has not needed a fill up, although I am having a hard time adjusting to a car so low to the road