Quote:
Originally Posted by rmay635703
Normally I don't mess with E85 anyway because its not $0.99 a gallon anymore like it was 7 years ago. Thus not worthwhile but with gas prices higher than normal I thought about testing the $3.499 e85 with non-e10 87 octane gas (most of the stations aren't selling it again, blast!)
Anyway this was mainly to test the fuel economy and performance aspects, I don't get the hop I normally get during cold starts but other than that performance seems similar (to the butt o meter) and FE per the lie o meter is within the margin of error but I definitely notice poor fuel economy during start up and better than expected once warm. So for cold weather in town = bad, highway = good
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I see. Yea at 3.89 a gallon I knew I was getting ripped off, but I am treating it as a cut price octane boost of sorts, and hoping that it will have some cleaning effect.
At 20% ethanol I didn't notice any different behavior other than an idle that dipped lower than usual for a few seconds making some unhealthy noises, and a more inconsistent idle while driving as the engine was adjusting the fuel trims or something. Engine was warmed up though, and no fuel economy loss apparent. This morning I started it at ambient (18C I think?) temperature and drove, felt exactly like using normal gas according to the butt-o-meter. Did not use the mpg gauge though, since I didn't feel like pulling out my phone. Supposedly 20-30% ethanol is the best for thermodynamic efficiency in some tests, I'm guessing it's a port injected engine thing where going too high in ethanol + port injection doesn't cool the charge enough to offset the unvaporized ethanol wasting some of the heat of combustion, whereas a direct injected engine makes better use of the cooling effect of ethanol and will see greater improvement from running a higher amount of ethanol.