Hello everyone,

I am on a week long ski trip out here in Colorado - and my rental car is a 2009 Flex Fuel Chevrolet HHR. There are limited E85 fueling stations out here, so the first two tanks I ran through the car was regular gas (85 octane out here - 87 is midgrade, and 91 is the high grade). Driving through some pretty serious mountain passes (tacking 5700 in order to maintain 60mph) I averaged 32.5mpg over 700+ miles. I found a station that had E85 (2.19 per gallon vs. 2.75 per gallon of 85 octane) and filled up. I knew there was going to be a drop in fuel economy using E85, but I was a little surprised at how drastic the drop was. I went from 32.5mpg on 85 octane to 24.4mpg on E85. I am only at 150 miles on the E85, so I'll update fuel mileage once I get back to Colorado Springs to return the car (at which point, it should have well over 400 miles on E85).

I guess my question is - an 8 mpg drop from regular unleaded to E85 seems to make the cost benefit of 56 cents per gallon irrelevant. I am not very good with math, and don't really know how to tackle figuring out cost per mile of each variable. I was just curious if anyone else has any experience with E85, and what your thoughts are on it.

I'm back to vacation now! Bye!

It's about being GREEN

E85 is better suited to turbocharged engines of small displacement and high compression. The e85 vehicles out there are just a compromise right now.

e85 has a 100+ octane rating... super grade in a good working engine that only needs regular will loose mileage in most instances... same thing for e85. the epa ratings for mileage are typically ~25% less than gas. i've heard it's prolly more like 10-15% in regular use. my family doesn't have any flexfuel cars, any one confirm?

and just remember, some of your tax money already went to help incentivise it's manufacture.

Edited March 20, 201016 yr by loki

Ethanol also has less energy per gallon. I have not tried it in the Impala even though I could since it doesnt seem worth it.

It's about being GREEN

It seems like it is about the PERCEPTION of being green. What is the carbon footprint of producing the corn used to manufacture ethanol? You have the fuel for the farm machinery to plant, spray and harvest the crop, then fuel for trucks to transport it, plus the energy needed to make the corn into ethanol. Is it really any more green?

Well, not all E85 is made from corn.... unfortunately, most of it is due to the corn lobby getting it's pitchforks into energy legislation.

E85 derived from algae or kelp is much more green than E85 from corn.

Looks like E85's only advantage is that it's for the most part renewable.