Bimmerfest - BMW Forums - View Single Post - What type of gas do you fill up with?
View Single Post
Old 02-12-2012, 07:27 AM
jimefam jimefam is offline
Officially Welcomed to the 'Fest
Location: Cumming, GA
Join Date: Jul 2010
Posts: 730
Mein Auto: 2011 550i on order
Originally Posted by nhs156 View Post
Hang on a minute. So if there's nothing but benefit of running with E85 fuel in an engine not designed for high content ethanol fuel, why won't car manufacturers honor warranty claims when they find out you've been running out of spec fuel? (A quick google on the subject last night appeared to confirm warranty denial across multiple brands, or at least serious concerns to that effect). I hear it has something to do with accelerated wear and tear on engine components that corrode much faster when subjected to alcohol, but then I'm no expert.
Now don't misunderstand what I'm saying I'm not telling you that if you put E85 into your M5 your gonna see some increase in performance because you wont, in fact your performance will probably suffer. However that isn't due to ethanol being a poor performance fuel it would be because your tune wouldn't be set up for it. If you did however adjust your tune you'd most likely see a good bump in performance but a good drop in mpg also. Your engine wouldn't be affected but the rubber in your fuel lines would harden and crack over time. Also if it was a motor that had been run for a long time with gasoline and you put a high ethanol content in it could clean the deposits in your gas tank and fuel lines and while that would be a long term benefit it could clog the fuel injectors and cause it to run poorly. These are simple things to avoid but if not accounted for it could cause problems. Ohhh and car companies try to get out of EVERY issue whether it's their fault or not. The problem with ethanol is the lower mpg and the higher cost vs gasoline but for pure performance it has a ton more potential than 93 octane gasoline.

Also I doubt the 10% ethanol in our pump gas would have negative effects since it is most certainly something BMW can plan for. If they can make adjustments for safety laws here and make little pointless changes like limit DVD while driving and take the psi readings out of the tpms system I'm sure they can change some fuel lines and adjust the tune for US spec cars.

Last edited by jimefam; 02-12-2012 at 07:32 AM.
Reply With Quote