MPG with Ethanol vs Unleaded

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XERO's picture
Joined: 3/23/04
MPG with Ethanol vs Unleaded

Has anyone really checked gas mileage comparing 10% ethanol to regular unleaded gas over a period of time? I?ve been doing it for awhile now. The biggest variable I run into is the wind, so you need to compare over several weeks or longer. What I have found is that my Silverado generally does about 1 MPG better with regular than with unleaded (that?s 13.5 vs 12.5 with light winds and pulling my boat). Ethanol costs me more per mile.

I don?t have enough data yet on driving with an empty load, so I can only comment on pulling a boat.

Ethanol costs us in at least four ways:
1. Higher cost per mile
2. Cost of taxpayer subsidies
3. Cost of state gasoline tax waiver on ethanol (I assume the taxpayers must make it up by paying more taxes)
4. Higher cost of food products and meat because of higher corn prices.

Yes, I know it?s supposed to reduce our dependence on foreign oil, but it sure looks like we?re getting screwed. Maybe we should go after our own oil harder and give up on ethanol.

SkeeterWX's picture
Joined: 7/14/03

Or maybe the auto manufactures should get ther head out of there @$#^%$# and build an engine made to run on ethonal! Not this crap of and engine made to run most efficently on 87 octane but CAN run on E85 when E85 has nearly a 105 octane rating! There is no way to burn both 87 dino and E85 at their peak perfomance in the same engine! One or the other will suffer subsantially.

BX2's picture
Joined: 12/25/07

Im not much of a mechanic, so i was wondering.What would be different in a ethanonal only engine? would it be,timing, the amount of fuel delivered,compression? Just curious.


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Ristorapper's picture
Joined: 12/27/01

I've tested the exact thing you are asking with my new 2008 Honda Accord over a period of two months. Not scientific by any means but what I came up with will not alarm anyone but give you an idea of what price to pay and still get your monies worth as far a just gas mileage.

I found that I can pay up to 13 cents more for Regular gas vs 10% ethanol by watching the mileage I get with each fill. UNderstand that I cannot/did not completely empty a tank of gas and fill it full with ethanol or regular so once I filled with a different grade it was a mix of gas I had in the tank.

I've kept log books on all my vehicles for many years now and to keep track of ethanol vs regular fill ups is just a matter of using an R for regular or E for ethanol behind the gallons I fill with.

It just basically gave me an idea that if ethanol is 10 cents cheaper than regular, which is uaually the case, I fill with regular.

I don't even want to get into the politics of ethanol and its production. But a little tit for tat is that I heard the production process uses a lot of petroleum products to produce that gallon of ethanol. Does it make sense, I don't think so.

Allen's picture
Joined: 1/9/02

I don't have the numbers with me, but I remember posting them on FBO in the past.

In both a 2002 F150 with the 5.4L engine and the wife's 2006 Explorer, I could just as well put in 10% water for the difference in mileage I see running E10 fuel.

I am very dissappointed in the E10 fuels as I can find no benefit to me or the nation in my burning it.

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bobkat's picture
Joined: 12/16/01

Yeah, we couldn't figure out why we always got 4 to 5 mpg more in our Prius burning regualar gas up in Canada versus burning regular here in USA. Thought they must have better gs or something till one day someone informed me that they don't have ethanol up there!
Now when we compare ethanol with regular down here we find the 4 to 5 mpg more with regular without alcohol. Makes sense because of the lower energy levels in the alcohol.
As far as I'm concerned the only reason to burn it is to help give the finger to the AhRabs when you fill up, although as Allen said, its a bit like putting 10% flammable water in the tank just to give the bird to the Arabs! Not a permanenet solution IMHO.
Its possible they could design an all alcohol burning engine I suppose. Haven't a clue how they would do it....They have them in some S A countries where about all they burn is alcohol. Any new technology would have to be able to burn all fuels here till the infrastructure for shipping fuesl is worked out.

Ristorapper's picture
Joined: 12/27/01

Of couse another benefit of ethanol is that in the wintertime it may aid in keeping fuel lines from freezing. For this reason every other tank of gas is ethanol for me when temps drop consistently below freezing.

luveyes's picture
Joined: 8/16/04

2-4 MPG diference in a 1997 Ford F150 4.6 ltr 5 spd. VERY noticable power loss for pulling. I hate ethanol.

Kaptain's picture
Joined: 11/6/06

Luveyes, I have the same truck and engine. I don't have the numbers anymore but I figured out that it definately cost me more money to burn 10percent ethanol at ten cents a gallon cheaper than it cost to burn regular unleaded. In my opinion, corn based ethanol is not the answer.

poorhunter's picture
Joined: 5/29/08

Has anyone tried the different ethanol blends? Many stations are running pumps that will allow you to blend your own cocktail. I tried this test on my own. I have a 2000 Ford F-150 with the 5.4L. I checked my truck with no ethanol as a base test, lost about 4% with E-10 blend. I GAIN about 9% with E-20 blend, plus it is 20 cents cheaper than regular, then I lost about 6% when I tried E-30 which was 30 cents cheaper. I don't have the flex fuel capable vehicle, but I had no problems with any of the higher blends. I actually thought my truck ran best with the 20%. I won't get involved in the politics of ethanol, but for me, price wins out over politics. I run E-20.

ranger3's picture
Joined: 4/9/05

Ethanol is not typically going to give you the same mileage as regular gas for a number of technical reasons that I've been told but don't understand. Actually, I believe someday if ethanol continues to exist it will be based on some other product than corn. I'm of the opinion that ethanol was a political solution and it is costing all of us far more than we know. First it takes more btu's to create a gallon of ethanol than we get out of it and in the process we pay a lot of taxes to generate it.

espringers's picture
Joined: 7/25/07

the research/studies indicating that it takes more energy to create ethanol than you get out if it are outdated and do not apply to todays ethanol production.

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Pro V1's picture
Pro V1
Joined: 12/28/01

Ethanol is a joke. 3-5 mph worse in my jeep w/V8. I know they say not to run it in newer outboard boat motors and I have run my last 3 tanks through my 1993 90hp yamaha and my fuel use is less and the motor runs better.


chesrr's picture
Joined: 11/6/06

Doesn't matter how they would build he engine....ethonal made from corn only has about 72% of the same potential energy as fossil fuel gas. Ethonal made from other cellulose sources have a higher energy content. For example Brazil gets about 88% energy potential of gasoline using sugar cane to produce ethanol. Brazil has managed to become energy independant due to using sugar cane based ethanol. Sugar cane also has a much higher level of biomass production per acre harvested. Too bad it will only grow in very limited portions of the states.

If you're using 10% ethanol (from corn) you will see approx 2.8% decrease in power and efficiency. By using E-85 there will be a significant reduction to a point where it doesn't pay for the cost/gallon savings.

snow's picture
Joined: 1/29/03


Anyone running on ethanol fuel greater than 10% in a "non-flex fuel" engine be perpared for some outof pocket expenses starting with the fuel pump...

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NDGixxerK7's picture
Joined: 2/13/08

Ok here are the numbers, regular unleaded has approx. 18,400 btu/lb where as e10 only has 17,700 btu/lb which dosn't seem like much but but that into gallons and you are looking at 4000 or so btu's. Now since in the combustion chamber heat is a big factor in efficiency you can see whty regular is better for mileage and performance. To prove my point look at #2 diesel it has approx. 24,800 btu/lb or 181,000 btu/gallon. and we all know how efficient a diesel is.

Now obviously air/fuel ratio's play a factor in this equation but with todays fuel injection they are all fairly equal.

Thats my 2 cents but what do I know I'm just a stupid mechanic!

webbuh's picture
Joined: 8/27/08

Here's some things to think about regarding ethanol. I may be less efficient but it at the same time is a higher performance fuel due to higher octane. Emissions are consdierably less when using ethanol as a fuel additive. E10 is about 4% cheaper than standard gasoline and it contributes to 1-3% loss of efficiency in MOST vehicles. Consider a month ago when the average cost of gas was around 3.64/gallon and the average cost of ethanol was 2.10/gallon thats 42.3% cheaper, even though ethanol is abound 33% less efficient. According to governmental research due to adding this renewable additive to our fuel, it kept oil futures down by over 27%. Oh and ethanol is not very that great in the winter since its hard for vehicles to sometime start due to the inability for ethanol to evaporate at lower pressures.

Tim Sandstrom's picture
Tim Sandstrom
Joined: 7/14/03

I don't think there is much of a change with 10 percent but straight ethanol.  It hardly makes sense and if the price difference between regular fuel and ethanol isn't exactly where it needs to be there is a net loss with driving with ethanol.

KFGO E-85 and 75mph vs. 55mph Test Drive Results
KFGO used 3 cars (2008 Chevy Impala’s) donated by Gateway Chevrolet in Fargo.

Our volunteers drove from the Radio Fargo-Moorhead studio to Bismarck and back.

55mph Car with Regular Unleaded
Little Don Hareland drove 55mph.

His car traveled 378.6 miles.

He used 11.4 gallons of gas.

The car driving 55mph got 33.21 miles per gallon.

75mph Car with Regular Unleaded
Big Don Clark drove 75 mph with regular unleaded gas.

His car traveled 378.6 miles.

He used 14.45 gallons of gas.

The car driving 75mph got 26.2 miles per gallon.

75mph Car with E-85
Scott Paul drove 75 mph with E-85.

His car traveled 378.6 miles.

He used 17.9 gallons of E-85.

The car driving 75mph with E-85 got 21.15 miles per gallon.

21.11% Better Mileage
The car driving 55mph got 21.11% better mileage than the car traveling 75mph with regular unleaded gas.

E-85 vs. Regular Unleaded
The car driving 75mph with regular unleaded got 19.27% better mileage than the car traveling 75mph with E-85.

But the E-85 cost an average of $3.18 per gallon versus regular unleaded costing an average of $3.84 per gallon.

Cost per Mile
The car driving 55mph cost 11.38 cents a mile for gas.

The car driving 75mph on regular unleaded cost 14.64 cents a mile for gas.

The car using E-85 and driving 75mph cost 15.05 cents a mile for gas.


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KFGO 55mph vs. 75mph Test Drive Results
KFGO used 2 cars donated by Corwin Toyota and drove from the Radio Fargo-Moorhead studio to Bismarck and back.

Both cars were 2008 Toyota Camry’s.

55mph Car
Harold Slaughter of West Fargo drove 55mph.

His car traveled 378.6 miles.

He used 12.0 gallons of gas.

The car driving 55mph got 31.55 miles per gallon.

75mph Car
Deane Williams of Moorhead drove 75mph.

His car traveled 378.6 miles.

He used 15.14 gallons of gas.

The car driving 75mph got 25.01 miles per gallon.

20.73% Better Mileage
The car driving 55mph got 20.73% better mileage than the car traveling 75mph.

Gallons of Gasoline Used in America
According the US Department of Transportation, there were 137.3 billion gallons of gasoline used on highways in America (2005 highway statistics).

Consumption is up from 2005.

28.46 Billion Gallon Savings
28.46 billion gallons of gasoline would be saved in a year if we drove 55mph (based on our test drive)

137.3 billion x 20.73% = 28.46 billion gallons of gasoline saved

$101.89 Billion Savings
Drivers could save $101.89 billion dollars by driving 55mph.

28.46 billion gallons x $3.58 per gallon (national average Friday)

Driving 75mph takes money out of the consumer’s pocket and puts it into the pockets of big oil.

360 Million Gallons Gas Used in North Dakota
Last year North Dakota used 360 million gallons of gasoline.

74.63 million gallons of gas would be saved in a year in North Dakota if we drove 55mph.

Drivers in North Dakota could save $267.17 million dollars by driving 55mph.



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Pikeman's picture
Joined: 12/16/01

Amen! Changed my driving habbits this summer such as breaking, passing, and not putting the pedal to the metal and keeping my speeds around 60 to 65 and noticed a jump in mpg on my 01 silverado.

XERO's picture
Joined: 3/23/04

You're right - speed can make a big difference. Driving my Silverado at 60 instead of 70 helps a lot. Strangely though, I have a V6 Camry that doesn't seem to matter if I drive 65 or 75. I suppose it's the dynamics. It's even more important to slow down when driving into a headwind or side wind. I'm not in favor of lowering the speed limit. I'm in favor of drivers slowing down to save on their own. If you want to pay more to get there, go ahead and drive faster.