I intend to find out with Avgas. I haven't seen any engine NOT run better on the stuff. I am lucky to have it within 2 kms of my shop. My ATV's , lawnmowers, weed-wackers, 31 ton log splitter,chainsaws, 5hp cement mixer, etc... all run better with it. Better in this case doesn't necessarily mean more power but easier starting, idle quality, throttle response, cooler running engines, happier engines is always the result. It's a real shame that lead will poison our nerves and kill us. Perhaps God is not a motorhead after all. J.Rob