[sho305]

In my G9 I took the governor off and ran it to max speed hundreds of times. It would run 28-31mpg gps depending on surface and tire pressure. What happens is they get up above 4K rpm and valve float. If you run float a lot it can trash the engine, so best to not hit that. So I would hit top speed and let off some it was fine at that, and never went faster down a hill. I ran synthetic in it and eventually many years later the rings wore out and burned oil, so I put a 420 clone in it that is much more fun. This on 22 tires. Given I didn't ride roads all the time either, so full speed was only once in a while and not very far.