Study Finds Ethanol Enhances Vehicle Efficiency
A new University of Nebraska study finds that higher ethanol blends increase engine efficiency.
The study, which was funded by the Nebraska Corn Board, found that high ethanol blends provide better energy conversion within an engine than other fuels, meaning less energy to travel further. The report says that e85 improved energy conversion by 13, 9 and 14 percent, respectively when compared to e10, for the light, medium and heavy loaded vehicles tested.
Vehicles went through chassis dynamometer testing as part of the study. The dynamometer simulated different road and vehicle operating conditions, allowing researchers to fully measure a number of important data points to measure the performance of different ethanol blends.
The researchers acknowledged that higher ethanol blends like e85 have a lower energy density, or fewer BTUs per gallon, than e10. That often leads to fewer miles per gallon for higher ethanol blends, but that gets partly offset by ethanol’s improved efficiency.
“While fewer BTUs typically means fewer miles per gallon, energy density is only part of the equation when considering fuel economy,” said Loren Isom, one of the researchers in the study.
“Fuel economy is actually a combination of fuel efficiency and fuel price, and on that point, higher ethanol blends may be the better choice,” said Isom, who is with the University of Nebraska’s Industrial Agricultural Products Center. “It just depends on fuel prices at the time. Specific vehicles may test out differently based on engine design and settings, but increased efficiency from ethanol blends make sense, and for the fuel prices we looked at in the study, e85 was the best choice every time.”
8 Comments »
Russ
The study found E-85 decreased mileage an average of 16%:
“..mileage only decreased 16%, 19% and 14% for the three models tested.”
Consumer reports tested a Flex Fuel SUV using E-85 and found it decreased mileage 27%.
Cyrano54
So many caveats invalidate the findings of this study. Lipstick on the Swine Species. People care about cost per mile, mpg, and driving the vehicle they want to drive. E-85 gives them none of these.
Mike1608
Cyrano54: e85 proved to be the most cost effective fuel in the study…meaning for the price, it was worth a moderate decline in mpg. In other words, e85 WAS THE LOWEST COST FUEL per mile for the vehicles studied, which is the exact opposite of the frequently cited myth you claim. Part of this is due to the high ethanol content improving the efficiency of the engine.
Russ: The Consumer Reports “study” I remember wasn’t really that much of a study. They looked at a single vehicle at a single point in time (some three years ago). Every vehicle is a bit different and adjusts to various ethanol blends in its own way. Certainly a single test of a single vehicle is not the best way to judge all flex fuel vehicles and ethanol as a fuel!?!
peabody09
I’ve filled my flex fuel Chevy Tahoe 80 times so far and have tracked mileage on every single tank. An 85% ethanol blend decreased mileage by 18%. Most of the time, the price discount for E85 more than offsets the lower mileage. What’s been more interesting, though, is that I get virtually the same mileage for blends ranging from E0 to E30. The mileage doesn’t start dropping off significantly until blends go higher than 30%. For my vehicle, that easily makes E30 the most efficient and economical blend. That’s real world, folks!
flee
My 1/2t GMC just finished a 1,600 mile trip averaging 22 mpg. The truck average, on a trip like this, will typically range 22-24 mpg with unleaded. I’ve learned switching between ethanol and unleaded will cause lower mpg. The engine controls must adjust or map to the new fuel. This may take a tank of fuel. Also, a quick change in fuel may cause engine light to go on. Now, if cold weather the engine will stumble upon warm-up burning E-85. I can adjust to this with gas pedal pumping much like the old days with carbs when this happens. If you do short trips in cold weather the E-85 not a good fuel as the fuel doesn’t vaporize as easy. Long trip in any weather a good fuel. Water doesn’t prose a problem with ethanol. Once warm the engine performs better with E-85.
I have three other older vehicles that utilize fuel injection and all burn E-85 well and operate like above. The gpm does drop, but surprisingly not much after the engine adjust to new fuel. The car controls takes a few hundred miles to adjust.
In summer and trips I prefer E-85. In cool and cold temperatures I continue to burn E-85, but for my daughters and wife suggest they burn unleaded (E-10) or if I splash blend will try to limit to E-50.
mjones
Your article demonstrates nothing less than Invincible Ignorance!
This is Junk Science at its worst! Communist Propoganda at its best!
Did you not read:
http://www.detnews.com/article/20090928/AUTO01/909280337/Carmakers-fight-hike-in-ethanol-at-gas-pumps
Are you ignorant of:
http://en.wikipedia.org/wiki/Energy_density
Do you have any idea how to conduct your own MPG tests in your own vehicle?
Not only does your “message” in the article convey a reversal of the laws of physics (or has Washington D.C. also revised these laws to suit their agenda?), but nowhere does it mention that ethanol requires massive subsidies from the government as well as massive subsidies in energy as well.
You can start getting a factual education right here:
http://healthandenergy.com/ethanol.htm
And how many times does the government have to lie to you before you start realizing you are being duped?
In the early 90′s MTBE was mandated as the answer to pollution and it was only after massive illnesses, accidents caused by engines stalling in traffic and contamination of water tables was MTBE “quietly” retired.
Are you too young to remember this? Well I lived through it!
My 84′ Toyota Pick up Truck which for years gave stellar performance and 22 to 24 MPG dropped to 13 MPG within the first tank or two of MTBE being introduced and it NEVER RECOVERED! The damage to the engine was done and my vehicle was ruined!
Just one of many government “experiemnts” done in the name of the “environment” using consumers as guinneau pigs.
And has anybody ever asked what would happen if there was a corn shortage? Never mind people starving, what would happen with the vehicles? Well, look no further than Brazil for their efforts in using their agricultural products for producing ethanol on a massive scale years ago. Then they had crop failures! Their ethanol vehicles wouldn’t run on gasoline and there was no ethanol available!
Unless you are one of those writers who’s mantra is “publish or perish”, get your head out of the sand, do your own research and report science, NOT PROPOGANDA.
M Jones
C Disher
For the last two years I have been driving a Dodge Charger with a 5.7 litter Hemi using an EPA certified conversion Flex Fuel kit. The high tech kit uses an alcohol sensor and a computer to help optimize engine performance real time. I keep a log of my fuel economy and savings. In the worst case, I lose 10-17% in range on E85 but the extra octane boost improves horsepower and torque on the high performance engine. The loss in range is offset by the much cheaper E85 fuel. Because I’m using a renewable fuel, the greenhouse gas reduction makes this engine just as green as a Prius based on the University of Nebraska CO2 reduction analysis.
So, I’m saving money on fuel, reducing my dependency on foreign oil, improving engine efficiency and performance, and creating jobs. E85 is clearly a better fuel for all of us.
Tazzi
To: MJones
this is from Wikipediea
Ethanol-based engines
Ethanol is most commonly used to power automobiles, though it may be used to power other vehicles, such as farm tractors, boats and airplanes. Ethanol (E100) consumption in an engine is approximately 51% higher than for gasoline since the energy per unit volume of ethanol is 34% lower than for gasoline.[17][18] However, the higher compression ratios in an ethanol-only engine allow for increased power output and better fuel economy than could be obtained with lower compression ratios.[19][20] In general, ethanol-only engines are tuned to give slightly better power and torque output than gasoline-powered engines. In flexible fuel vehicles, the lower compression ratio requires tunings that give the same output when using either gasoline or hydrated ethanol. For maximum use of ethanol’s benefits, a much higher compression ratio should be used,[21] which would render that engine unsuitable for gasoline use. When ethanol fuel availability allows high-compression ethanol-only vehicles to be practical, the fuel efficiency of such engines should be equal to or greater than current gasoline engines. Current high compression ethanol-only engine designs are approximately 20-30% less fuel efficient than their gasoline-only counterparts.[22]
A 2004 MIT study[23] and an earlier paper published by the Society of Automotive Engineers[24] identify a method to exploit the characteristics of fuel ethanol substantially better than mixing it with gasoline. The method presents the possibility of leveraging the use of alcohol to achieve definite improvement over the cost-effectiveness of hybrid electric. The improvement consists of using dual-fuel direct-injection of pure alcohol (or the azeotrope or E85) and gasoline, in any ratio up to 100% of either, in a turbocharged, high compression-ratio, small-displacement engine having performance similar to an engine having twice the displacement. Each fuel is carried separately, with a much smaller tank for alcohol. The high-compression (which increases efficiency) engine will run on ordinary gasoline under low-power cruise conditions. Alcohol is directly injected into the cylinders (and the gasoline injection simultaneously reduced) only when necessary to suppress ‘knock’ such as when significantly accelerating. Direct cylinder injection raises the already high octane rating of ethanol up to an effective 130. The calculated over-all reduction of gasoline use and CO2 emission is 30%. The consumer cost payback time shows a 4:1 improvement over turbo-diesel and a 5:1 improvement over hybrid. In addition, the problems of water absorption into pre-mixed gasoline (causing phase separation), supply issues of multiple mix ratios and cold-weather starting are avoided.
Ethanol’s higher octane rating allows an increase of an engine’s compression ratio for increased thermal efficiency.[19] In one study, complex engine controls and increased exhaust gas recirculation allowed a compression ratio of 19.5 with fuels ranging from neat ethanol to E50. Thermal efficiency up to approximately that for a diesel was achieved.[25] This would result in the MPG (miles per gallon) of a dedicated ethanol vehicle to be about the same as one burning gasoline.
Since 1989 there have also been ethanol engines based on the diesel principle operating in Sweden.[26] They are used primarily in city buses, but also in distribution trucks and waste collectors. The engines, made by Scania, have a modified compression ratio, and the fuel (known as ED95) used is a mix of 93.6 % ethanol and 3.6 % ignition improver, and 2.8% denaturants.[27] The ignition improver makes it possible for the fuel to ignite in the diesel combustion cycle. It is then also possible to use the energy efficiency of the diesel principle with ethanol.
(the link)
( http://en.wikipedia.org/wiki/Ethanol_fuel )
so in the short it works if you go all the way none of this piddly didly stuff and for a true “FLEX FUEL” some sort of boost needs to be in place such as an turbo
as far as what it does to engines what is out there each vehical has to be looked at the materials but then if your doing a full conversion well there you go
we can look to racing such as Indy cars are ran on E100 as of 2007
NASCAR started on it and theres talk of returning to it the American Le Mans Series moving to a blend of ethanol how about drag racing and the great one ethanol porwered lawn mower racing as far as long term ask some of the people that have been running on ethanol since the early 80′ like farmers go to yahoo and join one of there groups like
alcoholfuel@yahoogroups.com
and then ask (nicley please) about how long and what there results are well I hope this help and I hope more get there
“car drunk”
have a very good life
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