Mustang Dave is right: Adjust the way you drive. The beauty of hypermiling is that it can be done on any vehicle, regardless of size or weight. I drive an AWD Subaru Impreza (AWD is a huge drag on mileage). To make things worse, I need to keep a bunch of stuff in my trunk for work. The vehicle's a lease, so I can't modify it. Through hypermiling, I went from 19-20 mpg to 29-30 mpg. 50% improvement (I think that's right, or it's 33%).
