Quote:
Originally Posted by hfbmw
The Fitch is claimed to upgrade the fuel in the tank. Putting in regular will raise the octane to the middle grade. I try to use premium fuel with the main gas stations I use is BP. However the fuel changes for winter and of course the mileage drops due to the change as well as the engine doesn't warm up.  |
Engines, in my experience, perform better (performance and economy) running the octane they were designed for, not higher or lower.