Is anyone actually taking this seriously?!? I have a real hard time believing anyone in a 18000# vehicle is getting 25mpg (I'm not even going to address 37 mpg) let alone one with the aerodynamics of a phone booth. The aerodynamics of a bus are horrible because of the many things listed here (underside drag, frontal area, etc) not to mention the turbulence caused by anything with a straight flat side as well as the trailing turbulent stream of air off the back of the thing. We don't slice throught the wind, we crash broadside into it! Making any kind of serious difference in fuel economy would require a serious redesigning of the entire vehicle more resembling a supository than a brick. If you expect to make any honest experiments you need to broaden you test milage more than 50 miles or so. I bet you would see similar gains (or losses) depending on the day of the week, the temperature, the wind direction and speed of traffic, did your wheels travel the exact same path, etc. This is not a scientific study. A scientist searches for the truth by isolating the variables (say with a wind tunnel) and is able to repeat the numbers over and over to prove
the truth. He doesn't guess about anything like how much gas is left. He doesn't try to prove he is right. Put the lawn edging away and focus on a more attainable goal, like adding simulators to make it look a little less ghetto . . .
P.S. Eric, please don't take this too personal. You seem like a very likable inteligent and creative guy and have done some good work on your bus. I just can't keep my big mouth shut sometimes . . .