2000 BMW 740iL fueled with Food City 89 or 91 octane gas for years- then I decided to switch to ethanol-free gas to protect my chariot and then it revs in park like a ghost. I checked my floor mat and it was not near the accelerator. What have I done?? Should I go back to Food City ethanol gas (maybe 28% ethanol???) or stick with my new crusade to only use ethanol - free gas.... maybe I should go to Farm Coop instead of Weigel's? What happened?
give it time to adjust
maybe 28% ethanol???
what do you mean? Normal pump gas should be max 10%. Maybe 15.
ethanol-free gas to protect my chariot and then it revs in park like a ghost.
A 2000 BMW 740iL is designed to use 10% ethanol gas. Cars have been designed to use unleaded fuel (Gasoline with 10% ethanol) since the late 70s. My '79 Pontiac has "Unleaded Fuel Only" written on the dashboard. When you're using a carburetor, if you have ethanol laced gas, it tends to gum up if you don't use it regularly. You also destroy rubber parts if they're not designed for ethanol. The gasoline hardens and embrittles rubber if it wasn't intended for 10% ethanol gas. This is not so for fuel injected engines. Simply using it regularly will keep parts from getting gummed up.
Straight gasoline also has a lower octane rating than "gasohol", which means more of a tendency to prematurely detonate as opposed to a controlled ignition. Aviation gasoline is also not just straight gasoline, it's still blended with tetraethyl lead, for example. I believe straight gas has an octane rating of 85, regular 10% ethanol gas has a rating of 87, and premium is 92. Straight gasoline is intended for lawn mowers, weed eaters and things like that. Most aren't designed to withstand ethanol laced gas and their carbs will embrittle.
