Skip to comments.Study Finds Certain Ethanol Blends Can Provide Better Fuel Economy Than Gasoline (???)
Posted on 12/05/2007 9:29:42 AM PST by Red Badger
Research findings released today indicate that mid-range ethanol blendsfuel mixtures with more ethanol than 10% (E10) but less than 85% (E85)can in some cases provide better fuel economy than regular unleaded gasoline, even in standard, non-flex-fuel vehicles. The new study, co-sponsored by the US Department of Energy and the American Coalition for Ethanol (ACE), also found that mid-range ethanol blends reduce harmful tailpipe emissions.
Previous assumptions held that ethanols lower energy content directly correlates with lower fuel economy for drivers. Those assumptions were found to be incorrect. Instead, the new research suggests that there is an optimal blend level of ethanol and gasolinemost likely E20 or E30at which cars will get better mileage than predicted based strictly on the fuels per-gallon Btu content. The optimal blend varies with the vehicle, according to the findings.
The University of North Dakota Energy & Environmental Research Center (EERC) and the Minnesota Center for Automotive Research (MnCAR) conducted the research using four 2007 model vehicles: a Toyota Camry, a Ford Fusion and two Chevrolet Impalas, one flex-fuel and one non-flex-fuel.
Researchers used the EPA Highway Fuel Economy Test (HWFET) to examine a range of ethanol-gasoline blends from straight Tier 2 gasoline up to 85 percent ethanol. All of the vehicles got better mileage with ethanol blends than the ethanols energy content would predict, and three out of four actually traveled farther on a mid-level ethanol blend than on unleaded gasoline.
In addition to the favorable fuel economy findings, the research provides strong evidence that standard, non-flex-fuel vehicles can operate on ethanol blends beyond E10. The three non-flex-fuel vehicles tested operated on levels as high as E65 before any engine fault codes were displayed. Emissions results for the ethanol blends were favorable for nitrogen oxides, carbon monoxide and non-methane organic gases, showing an especially significant reduction in CO2 emissions for each vehicles optimal ethanol blend (E20 for the flex-fuel Chevy, E30 for the Toyota and Ford, E40 for the non-flex Chevy).
Ethanols energy content was not found to be a direct predictor of fuel economy. All four vehicles tested exhibited better fuel economy with the ethanol blends than the Btu-value estimates predicted.
E20 and E30 ethanol blends outperformed unleaded gasoline in fuel economy tests for certain autos. Contrary to Btu-based estimates of fuel economy for ethanol blends, three of the four vehicles tested achieved their highest fuel efficiency not on gasoline, but on an ethanol blend. Mid-level blends of ethanol E20 (20% ethanol, 80% gasoline) and E30 (30% ethanol, 70% gasoline) offered the best fuel economy in these tests.
E30 offered better fuel economy than gasoline (a 1% increase) in both the Toyota and the Ford. *
E20 offered better fuel economy than gasoline (a 15% increase) in the flex-fuel Chevrolet. *
The non-flex-fuel Chevrolet more closely followed the Btu-calculated trend for fuel economy, but did experience a significant improvement over the trend line with E40 (40% ethanol, 60% gasoline), indicating that this may be the optimal ethanol blend level for this vehicle.
The standard, non-flex-fuel vehicles operated well on ethanol blends beyond 10%. The Ford Fusion operated on E45, the Toyota on E65, and the non-flex-fuel Chevy on E55. No engine fault codes were displayed until these levels were surpassed.
I can’t imagine why the University of N. Dakota would find such positive results for ethanol.
I will love to hear Mobile’s rebuttal of this....
Odd also ... no one sells the 20% or 30% blends. Am I wrong?
Higher compression ratios, higher expansion factor on the downstroke, etc.
Ethanol raises effective octane levels. If you could depend on 10 to 20% ethanol in the fuel, you could require Detroit to up the compression ratio on gas engines to, oh, about 12:1 from the current 9.5:1.
In the midwest, there’s some facilities where you can ‘blend your own’ as it were.
Hmmm Fuel with less energy will do more work. makes sense to me (as long as you repeal the first law of thermodynamics - something that Kongress has done with the CAFE standards.) Maybe that's how they found that you can get more work out of less energy. They ran the study after Kongress repealed the first law.
You mean Exxon-Mobil?............or the one in Alabama?...........
Ethanol is not a green fuel. It is a boondoggle shoved down our throats. If Ethanol is a viable substitute for gasoline, remove the subsidies and mandates. The public will choose the market place winner. Unfortunately, the ethanol boosters know that ethanol is a loser. Thus, they lobby endlessly to continue this boondoggle.
I do not believe this study. E10 and E85 have both been demonstrated to reduce fuel efficiency. I see no reason why other blends would increase efficiency. Ethanol also has corrosive effects so I see no reason to put it in my tank even if it had some small fuel efficiency improvement.
The ethanol doesn’t burn but turns to “steam” instead creating more force than the gasoline alone...............
Just a thought......
How long on octane are current refineries that they would need to boost it with corn ? Get by the “octane increase” claims and you’ll find the real ethanol contribution is rather pointless.
Great, so you drive up to he pump, and enter your vehicle's make and model, and the pump mixes it for you.
Yeah, THAT's gonna work.
Or maybe each vehicle has a gasoline and an ethanol tank, and it mixes them itself.
Yeah, THAT's gonna work.
My keyboard is dyslexic, two...;0..
Water injection has been used to increase engine efficiency. Also, some people suggest that engines perform better in high humidity environments. Could the ethanol produced commercially contain some water?
With much higher compression you’d have to redesign the engine with more strength and weight, thus a negative impact on real mileage. This really becomes a factor on diesels, with far higher compression, but can’t be ignored even in the 12:1 range, IMO
The results of this study seem to defy the laws of physics...
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