E10

[Fuzzy5150]

I know the big push is for increasing ethanol use, especially in NE where I live. We are #2 in the nation for production.

For 7 weeks, using regular 85 oct unleaded, I have averaged 47.14 mpg. Currently, there is a $0.10 difference in the cost of reg. unleaded and E10, so I decided to give it an honest try.

In the last 2 weeks, and for 2 tanks full, my average dropped to 41.4 mpg.

I travel a very stable 70 mile, round trip circuit each day, employing the same 'hypermiling' techniques, so believe the results are as accurate as I can make them.

With price points of $2.95 and $3.05, that represents a 3.28% differential in price, but my mileage dropped by 12.81%.

Based on those results, I would have to buy the E10 at $2.68/gal to stay scratch.

What results have other posters had with E10?

[cems70]

I can't get straight unleaded "non-ethanol" gas where I am (Rhode Island), so I have no way of measuring the difference in fuel economy between ethanol and non-ethanol gas. However, I do remember with my previous car ('95 Civic VX) that I got about 5% better FE when I filled the tank in Vermont where MTBE was not required because they didn't have enough unhealthy air days to require the additive. MTBE had the same affect as ethanol in reducing emissions and lowering FE.

To this day, I'll never understand how it's possible to burn more gas with ethanol (or previously MTBE) gas yet produce fewer and cleaner overall emissions than burning non-ethanol or non-MTBE gas. The cleaner emissions must be pretty substantial. But we, as consumers, pay for it twice: 1) in the extra cost per gallon for the blended gas (I see you pay less for the ethanol blend, but my understanding is the blended stuff, at least years ago, added to the cost of a gallon of gas) and 2) for the worse fuel economy with the blended gas.

[ELF]

Welcome Fuzzy, I missed your intro thread.
What octane was the gas with E-10 ? Seems like a pretty big loss in mpg.
All gas here in MN is E-10, but I can hop over to WI and get straight gas. AS far as I can see there is only maybe 1-2 mpg difference, One thing I noticed is that mpg is always the same with gas, mpg seems to jump up and down more with E-10, possibly due to some tankfuls absorbing moisture.

[minic6]

What you have found is quite reasonable results. Higher the ethanol lower the fuel economy. My wife asked about it for our Buick which it's not made to accept. I figured it would have to be 45 cents less per gallon, which it isn't in our area to make it a wash. If your car is not made for it, don't run it for prolonged periods as it can be caustic to your fuel system. That is one of the major differences, plus most cars either use an ethanol sensor or a new algorithim in the ecm to figure how to set up to run on it.

[skewbe]

Yah, less energy density in ethanol.
http://en.wikipedia.org/wiki/Energy_density

Gasoline: 34.6 MJ/L
Ethanol: 24 MJ/L

But it is renewable at least, or at least has more potential to be renewable if we didn't waste so much gas making it.

[SVOboy]

When ethanol was first phasing in I alternated in my gramma's crownvic and my car, so no difference, but everyone's reacts differently to it I spose.

[minic6]

Gas usage to produce it is a real problem some studies show it can be more than gal. for gal. I hope they get this fixed! One thing though for those that like power it is a real powerhouse like getting some great premium.

[88HF]

Originally Posted by minic6

Gas usage to produce it is a real problem some studies show it can be more than gal. for gal. I hope they get this fixed! One thing though for those that like power it is a real powerhouse like getting some great premium.

I believe you may be wrong on several points here. First ethanol I believe has less BTUs than does gasoline, so less performance. Second, high octane "premium" gas does not improve performance. High octane is only necessary for high compression ICEs to defeat pre-ignition or detonation. Basically when the gas/air mixture gets too hot from compression it will ignite before the spark plugs go off and it will try to send your crankshaft in reverse.

[zpiloto]

Here's some more discussion on it.

[minic6]

All I know is there is real positive diss. on using it in some of the higher performance cars out there.

[Ryland]

I've noticed the same kinds of drop in mileage with E10, and I try to avoid it when possible, I also notice that at least a year or so ago when in MN, that the BP gas stations sold premeum that was 100% gas, and was labled as being ment for only older cars, motorcycles, lawn mowers, and cars that can't handled ethonal.
besides the higher then 10% drop in mileage with a 10% alcohol content in the fuel, I also don't like like it because when corn is mono croped (as almost all corn is) it causes horble soil erosoin, and depletion of nutrents, causing farmers who are looking for a few more pennies, to start spraying more and more, poisioning our ground water, and rivers.

[minic6]

According to FutureCar 100% ethanol is 115 octane. Much higher than the premium blends you can buy. Higher octane equals higher comp. ratios possible, making it possible for higher horsepower.

[Fuzzy5150]

Elf, The E10 we get in NE is 89 Octane, vs 87 Octane for regular unleaded gas.

[ELF]

The reason I was asking was, higher octane in some cars can cause lower mpg. Many newer cars will advance the timing to take advantage of the extra octane.

[Ryland]

Alcohol engines are closer in design to a gasoline engine, then say a Diesel engine, but alcohol engines are enginered to run at their peek on alcohol, not gasoline, same with gasoline engines, they are not designed to run at their peek on alcohol, sure you can mix small amounts of diesel, or alcohol, or water in with your gas, and run it in your gasoline engine, but it will not run at it's designed peek efficentcy, I think Saab overcame this with a variable presure set up on a turbo, so they could very the affective compression ratio of the engine to run on either gas, or alcohol, but so far that is the only one that I have heard of.
I really think it's a bad idea that we are burning more gasoline because of the alcohol in the fuel, I've heard of people who have their mileage drop by as much as 20% with E10, so if I took a gallon of gasonline, and added 1/10 of a gallon of ethonal to it that gallon of gas will not take you as far.

[shivik]

As other guys pointed out:
To proper utilize E10 you have to adjust your timing(forward).
Higher octane fuels generally burn slower / than normal gas
Higher octane does not equal more power.
Octane rating just says how stable is the fuel when compressed before it self ignites.
What typically happens in the engine is that fuel mixture come in the combustion chamber it gets compressed and ignited.
Then comes the difference-while it burns slower the exaust valves open
and it is being pushed out by the piston while still burning.
Meaning that the fuel mixture has not yet gave 100% of its power to the engine,resulting in some loss of power and hurting FE.
The point of advancing the ignition is to give the mixture more time to burn
completely (before the exhaust valves open) by igniting it earlyer.

[Fuzzy5150]

I can appreciate the different combustion properties of ethanol, but would prefer if the engine management system could automatically compensate. I really don't want to start altering the timing.

[zpiloto]

Originally Posted by Fuzzy5150

I can appreciate the different combustion properties of ethanol, but would prefer if the engine management system could automatically compensate. I really don't want to start altering the timing.

Some cars will see a decrease in mileage others a increase and others no change. I would start looking for other reasons beside the E10 for a 12% decrease. That seem rather extreme for E10.

Take this with a grain of salt because it come from Ethanol intrests but this have the average loss at 1.5% for E10. YMMV

[Fuzzy5150]

From the outside, I would also agree that a 12%+ drop looks 'fishy', but I ran the E10 for 2 weeks, which is 2 tanks full.

I drive the same route, and employed the same driving techinques that got me to 47.14 with regular unleaded. Enviornmental conditions were the same, in terms of weather, a/c use, etc.

I have hence had 2 weeks back on the unleaded, and my mileage bounced right back.

I use syn oil, changed every 10,000 miles. I am mid way in an oil change. I change the air filter every 2 oil changes. I check air pressure in tires every Sunday, and make sure they are 44 psi. I change spark plugs every 30,000, and use Bosh platnium 4's. I really don't believe there is any radical variability. If there were, my mileage would not have rebounded when I went back to unleaded.