wolfman

For those of use who have flex fuel HHRs, I have concluded a limited experiment with my HHR running it on E85. The figures are a bit more limited than I'd like, but the HHR is not being used as my commuter vehicle, so this actually represents tank fills going back to early September.

I took the two fills on my HHR on pump gas that were representative of my normal driving conditions. They were 33.1 and 32.8 mpg respectively. This averaged out to 32.95mpg. Despite the low fuel warning on the DIC when I filled the tank, the first fill of E85 was what I call a transitional tank, so I threw that number out, since it would not be a "true" E85 sample. I then took the next two fills, which resulted in 25.8 and 25.3 mpg respectively, averaging out to 25.55mpg. The loss was 7.4 mpg, or a 22.5% drop in economy. For those who wish to use E85, but want to make sure that they are saving money in the process, this means that E85 needs to be ~23% cheaper than the E10 federally mandated pump gas to save money. I don't have access to ethanol free gas in my area to correlate to zero ethanol. My past records however, have never shown any statistically notable difference between RUG and E10 in any of my past vehicles.

millerrdjr

Thanks for publishing your results. Confirmation of my expectations.

sethwas

Correct, but cheaper than which octane.
Since E85 is super high test (105+ octane) do you compare it to 87, 89, 91, 93, or 94/95 (if available by you)?

As of this postings date in Miami, using gasbuddy, E85 is
11% cheaper than the cheapest 87
15% cheaper than the cheapest 89
19% cheaper than the cheapest 93

For reference E85 is
21% cheaper than the most expensive 87
26% cheaper than the most expensive 89
28% cheaper than the most expensive 93

On average you are looking at
16% cheaper than the cheapest 87
21% cheaper than the cheapest 89
24% cheaper than the cheapest 93

So, locally, as long as you don't fill up with low test you 'beat' gas by choosing E85.

Seth

ChevyMgr

If you are going to use E85 there are some things you need to know.

It is not recommended that you switch between E10 and E85 every other tank fill up. If you do 3 E85 fill ups to every 1 E10 fill up you should be ok or vice versa.

Never change from E85 to E10 or vice versa and pump the gas with the KEY ON or the ENGINE RUNNING. The system will not know you just added fuel and your vehicle will think it has 10% ethanol when it has 85% and the vehicle may not run, run poorly or get a CEL.

After changing from E10 to E85 you should drive the vehicle a minimum of 6 miles.

John H

A local dealer has a 2009 HRR on his lot, with 10,000 miles on it, that I looked at this evening. It is a E85 model. Has anyone here had any problems caused by the E10/E85 system itself? Of course I would expect a drop in gas mileage with E85 being that alcohol has around half the inherit potential energy of straight gasoline.

Thank you Chevy Mgr. for the "KEY ON or the ENGINE RUNNING" info! Duly noted!

By the way "sticker price" was $16K. I test drove it and I know it would suit my needs. Still, the "sticker price" needs working on before I would "sign the dotted line".

BlackknighT

When the E85 by me was .80 cents less than the regular gas it was worth it to lose a little mileage. Now the prices are so close it is now NOT worth it. With all the 15 mile an hour traffic going home 27 miles from work-E85 would be killing me.

Not only should price be a factor in using the E85, but the daily conditions you encounter. Some of the E85 web sites (govnmt ones) will tell you if your vehicle is great for E85 mileage and how much it would cost per year-ours is not worth it. Surprisingly some of the chevy V6s do better.

Made a 100 mile straight run with little traffic from LI to NJ to an outlet mall-did 34.6 mpg on the DIC (some of the trip was with the cruise control, with some stops on the cash line for tolls). Going home all was right with the world until getting off the Verrizano Bridge into Brooklyn on the Belt-but even with that I got 29.4 mpg by the time I made it home. I reset the DIC before going and coming.

My daily mpg varies (trip from LI to Brooklyn) from 23 to mid 26s when I run the DIC for the week without resetting it. All in all it is costing me only about $60 dollars a month more than if I had kept paying for gas in my Olds 350 with 4 barrel to pay for the new HHR. The Olds had a 26 gallon tank-NY gas prices on average cost me about $70 a week just for turning the key to go to work-not including small side trips. Was definately worth CFC for me-even though I miss "driving my living room couch to work".

Just my 2 cents for my daily driving conditions.

John H

Now here's an interesting, but long, read in regards too Flex fuel.

http://auto.howstuffworks.com/fuel-e...uel-works1.htm

Still my question is,...has the system that adjusts between E10 and E85 been a problem for some owners?

BlackknighT

Not for me & I now have about 10,000 miles on my 09 bought at the end of 08/09.

John H

Thank you BlackknighT!

FWBeck

In essence, the only figure worth comparing is "MP$" — miles per dollar regardless of fuel, be it E5, E10, E85, diesel, or electricity.