Terry, Great accomplishment! I have not had the warm weather or flat terrain to acheive those numbers yet but I know the HCHII can do it. Is that correct that you put 55 psi in your tires?!!? I went up to about 48 psi. That did well for me for a while, however for the whole month of March we had very strong winds here and I found myself battling with the car to stay in the lane and to achieve good FE. I lower back down to 42 psi, and now everything is much better. The wind has since left Maryland, so I may try and air up again.