E85Forum.com

BlownEthanol · Joined: 08 May 2007 Posts: 43

From a racing standpoint, $2.75 a gallon for 105 octane gas is amazing so no problems there.

I was looking into the benefit of converting my DD to E85 but at ~30% more fuel on average that it would consume on E85, the $2.75 a gallon I pay for it at the pump makes it seem more like $3.58 a gallon compared to gasoline.

Does it cost this much everywhere?

hotrod · Joined: 19 Apr 2005 Posts: 872 Location: Colorado

No, and you economics are probably better than they look.

I If I drive for economy, I get 22 -24 mpg on 100% E85 vs a long term average of 24 on gasoline. If I blow off economy and drive normally I get 17 -19 mpg. That puts my cost per mile for normal driving about the same as getting 27-28 mpg on gasoline and 32+ mpg when driving for economy.

Prices are up here as well, I just bought a tank at 2\$2.46/gal but premium is about a dollar more at 3.33 - 3.49 depending on where you buy it.

Your fuel economy won't be as bad as the difference in fuel injection rate implies. Fuel milage is not closely tied to the energy content per gallon. It also depends on drivability issues and tuning issues. Because of the higher octane a high performance engine can be run with much better ignition timing that it could use on normal gasoline. You also have better torque characteristics so you spend less time in higher throttle settings and can pull a taller gear at lower rpm.

Several of us with Subaru WRX's are getting about 92% or our gasoline economy.

Larry

BlownEthanol · Joined: 08 May 2007 Posts: 43

Well I just filled up the car yesterday for $3.04 a gallon! Still cheaper than gasoline and still cheaper than race gas by far, but its not making a good name for itself this way. I mean I always heard that E85 prices would not fluctuate like gasoline.

Revision · Joined: 14 Sep 2005 Posts: 194 Location: Carol Stream, IL

Its because of two things.

1) Pricing is set by the blender which is normally the oil refinery and they are not going to shoot themselves in the foot.

2) Ethanol is used to replace gasoline. Its value will fluctuate a bit like gasoline based on how much there is to go around.

Right now fuel ethanol prices are fairly stable. We just are not getting passed the benefits.

http://www.energy.ca.gov/gasoline/graphs/ethanol_18-month.html

I've got logs that show that I am either getting a worst case milage of 25% loss or a best case milage of 8% loss. The average is somewhere in the middle. Wink

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Its a lot of fun when I can infuriate someone by telling them about the 30% fuel requirement and they jump on that to make the argument that E85 isn't cost effective. Then I tell them about my worst case gas milage of 25%, and they'll jump on that too, but can't explain why I didn't lose 30% gas milage. Then I'll smack them with the 8% mpg loss best case and when they can't explain why, I'll start telling them about the properties of burning Ethanol. By then they're usually hooked. Wink

GM is doing something wrong with their flex fuel vehicles. Setting up a car to run on 87 octane then trying to dump 105 octane fuel in it and make it run just seems wrong to me. Now if they'd tune an engine for premium and then use 105octane E85 to bump the power they'd have a more efficient engine that would get better milage.

Oh well, here is to hoping that GM will use Direct Injection in the near future to more efficently use E85.

GM Announced Direct Injection V6.. See Link.
http://www.greencarcongress.com/2007/05/gms_first_v6_di.html

Alcohol · Joined: 17 Apr 2007 Posts: 634 Location: Central Wisconsin

GM is doing something wrong with their flex fuel vehicles. Setting up a car to run on 87 octane then trying to dump 105 octane fuel in it and make it run just seems wrong to me. Now if they'd tune an engine for premium and then use 105octane E85 to bump the power they'd have a more efficient engine that would get better milage.

Oh well, here is to hoping that GM will use Direct Injection in the near future to more efficently use E85

Amen Revision!!! Very Happy

BURNALCOHOL · Joined: 19 Oct 2005 Posts: 50 Location: Raymond,NE

The 30% number comes from the difference in energy in an open flame. But it is more like 15% difference in a combustion engine(in a normal FFV), because of the better burning characteristics of ethanol. Not as much power loss going to waste in the form of heat.
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Jeremy Nicholls

Turbo98 · Joined: 03 May 2007 Posts: 100 Location: Misouri