seems to me the more miles i put on the burger, the better the gas mileage gets. last year the wife & me went to calif. at one point we were on the freeway running between 75-85 mph. and the gas mileage was the lowest i ever recorded. 39 mpg. just recently we went to bisbee ariz. and on the return trip we were riding I-10 at a sustained 85 mph and the burger returned 50 mpg. i have a little over 9000 miles on the burger. the rear tire is shot and i'm waiting for my new one. hi ted.