Is Ethanol Robbing Me Of MPG?
 

As you may know, the Commonwealth of Virginia mandates 10% ethanol in every station's fuel tanks. :rolleyes:

I've been told this costs us about 10% on efficiency. :mad:

What do the experts here say? :confused:

Yes. Ethanol provides less energy per unit volume, and the A/F ratios are not the same, so more ethanol is consumed.

This has been known since carburetor days when larger jets had to be used when running ethanol.

Bollocks!

Is it harder on an engine that isn't a "FlexFuel" vehicle? I'm pretty sure the German engineers who designed my car in the 1980's didn't do so with 10% ethanol in mind.

It'll make it run a bit leaner, but probably not 10% leaner, as the ECU has adjustment available. I don't think 10% counts as "flex fuel" anyhow.

10% seems like a bit much. I loose about 2 mpg or so on the Matrix when using E10. They do this because ethanol burns cleaner than gasoline.

Comparing the energy content of ethanol and gas, E10 has 3.2% less energy per gallon. It raises the octane, though, so, as always, YMMV. Studies have shown reductions in the 2-3% range.

Higher octane than necessary reduces efficiency, as the burn is cooler. Increased octane is of no benefit if there is no pinging/detonation or the ignition can't be advanced to take advantage of it.

While this is true, I think it's fair to say 87 octane e10 is 87 octane in the same was the 87 octane non-ethanol gas was 87 octane before the ethanol mandates.

Hello,

I believe that ethanol adds some necessary oxygen to the mix, so it burns cleaner. Whatever the reason, it is there -- something has to replace the MBTE since that crap was/is messing up the groundwater.

Interesting to note, MTBE has about 80% the energy of gas, while ethanol has about 67%. So moving from an MTBE mix to ethanol is about the same drop as moving from straight gas to MTBE.

http://www.epa.gov/otaq/regs/fuels/ostp-3.pdf
http://tonto.eia.doe.gov/oog/info/twip/twip.asp

It's funny you should mention this. I filled up last time at Costco fuel center. They say they use 10% Ethanol in their fuel (not up to 10%, just 10%) and so far, this tank has gone farther on X amount of gas (whatever X turns out to be) then any tank previously. I will know for sure what the millage exactly is when I fill up (probably today or tomorrow), but judging by the gauge, I just broke below the 3/4 line and I've already gotten about 180 miles (I have a picture of it at 100 miles with the needle still right at the top from this tank, but it's on my phone). So either I'm doing something very very right this time or ethanol is causing my car to run leaner, not spray more fuel.

I agree with the second part, but do you have a source for the
"Higher octane than necessary reduces efficiency, as the burn is cooler. "
part. I would have thought the flame temperature would be controlled by only the heating value of the gasoline, and the amount of air in the mixture. Unless you meant that the heating value is reduced by WHAT they add to the gasoline nowdays to make the octane higher, since sadly that yummy tetra ethyl lead is no longer available. ;)

Frank Lee
That is a very interesting link. They don't seem to explain "why" this is going on, I wish they did. Perhaps the burn is faster, so more of the heating values is used for power rather than for heating up engine parts? Also I wish we made ethanol from something other than food, but that is a different rant.. :D

Actually I read a few days ago that in areas that require e10, the regular gas may be the same octane as mid-grade or premium. I looked but couldn't find the article.

Flexfuel vehicles are a joke. They just have a few gaskets and rubber lines replaced with materials that won't corrode under high alcohol concentrations. E10 is too diluted to do anything.

I say look at the big picture. You are losing 3% in mileage to vastly increase the health of yourself and the environment. Not all things of value have $ signs preceding them.

What's interesting is that ethanol, gallon to gallon, is generally cheaper than gasoline. Premium gasoline, which contains more ethanol by volume, is more expensive than regular.

- LostCause

flex fuel vehicles have more done than that, the computer can sense the difference in fuel and adjusts the amount of fuel used so that you get proper burn, this is not done in regular vehicles that is why regular vehicles cant run e85. now if you dont use e85 and your vehicle is flex fuel, that is where the joke comes in.

but from my experiences, e10 and e20 do not give every vehicle decreased mileage, in fact my highest mileage (in jeep2) prior to modifications was 19.91mpg and that was with e20, i increased tire pressures and have maintained an increase since then but have not used e20 since that tank. i am considering using e20 exclusively though.

It is true the computer will change the A/F ratio to stoich, but it's a joke because the ethanol is essentially being wasted. It's the equivalent of buying premium gasoline for a grocery getter.

Ethanol belongs in an engine running an 11:1 or greater CR. Flexfuel vehicles only exist for governmental reasons. It's a way to meet environmental standards cheaply, without the requisite of actually doing anything.

Things may be different in the corn belt, but in California I doubt any flexfuel vehicle has seen a drop of E85.

- LostCause

i agree with you, most flex fuel vehicles never see more then e15, i had a town and country which was flex fuel and i used e85 in there every time (with negligible mpg loss (1-2mpg)) but when i was in NC the closest place to get it was an hour and a half away so i never got it there

I run E85 in non-flex fuel vehicles.

Ethanol does produce less energy per gallon, but FE does not go down proportionally, torque does. So, to get the same torque you'll open the throttle more, reducing pumping losses (improved volumetric efficiency). Depending on the engine, gearing, and load you may improve your overall efficiency faster by reducing those pumping losses faster than you're losing out due to the lower energy content.

For what it's worth, here is an EPA estimate for a Flexfuel Chevy Tahoe 1500 2WD:
City Hwy
Gas 14 20

E85 11 15

The E85 comes out ahead in the EPA's "Carbon Footprint" rating (tons/yr of CO2): 9.2 vs 11.4.

I've never seen E85 here in New England, so I'm curious how much is a gallon of E85?

around here it is between .40 - 1.00 less than regular, i'll drive by the station today and tell you todays price difference

I'd be careful of doing that -- best to follow the directions in the vehicle's book on fuel.

Having been switched to e10 in our area, expect to see a decrease in mileage. Maybe around 4%. Burns cleaner, but you get less mileage... Not a good trade-off. Potentially much worse for the environment and your vehicle. Definitely worse for your wallet.

ethanol is bad for everyone, it decreased the amount of food availible for eating (and exporting to poor nations as aid), increases the cost of food, rasises our taxes (ethanol production is not profitable, it's HEAVILY subsidised), takes more energy to produce than you get out of it, can can drop MPGs. what is the benefit?

Have you seriously looked at food subsidies?
Are you familiar with the term dumping before you say high food prices is bad for the third world?

This is propeganda, as modern studies dont support this claim. It WAS only true of corn ethanol anyway.

Carbon neutral fuel.
Octane of 116 in its pure form.
Oxyegenate when mixed with gasoline
Much more ecologically friendly when spilled into the ground.
Has antifreeze properties when mixed with gas for winter use.
Ethanol has solvent properties that keep engine components cleaner.

What other method of ethanol production is available in this country? So far, NONE. Cellulosic is only now beginning on a tiny scale. Sugar cane can only grow in small areas of the gulf coast. It's all corn.

E10 works in most cars, or so I've heard. But E10 can cause problems for other vehicles; sometimes the mix out of the pump is actually higher than 10% ethanol, and for some motors like outboards and inboards on boats, it can cause quite a few problems. I think its related to releasing deposits in the tanks, but I'm not sure.

Anyway, be careful using E10 or anything higher in ethanol in non-automotive motors.

The real benefit of flex fuel would be to burn methanol. That you can get from digesting wood scraps and all sorts of trash.
Robert Zubrin on Making Oil Compete on National Review Online
From the article:
"
However, there is now a way to break OPEC, a surprisingly simple one. What is needed is for Congress to pass a law requiring that all new cars sold (not just made, but sold) in the U.S. be flex-fueled — that is, be able to run on any combination of gasoline or alcohol fuels. Such cars already exist — two dozen different models of flex-fuel vehicles (FFVs) are being produced by Detroit’s Big Three this year — and they only cost about $100 more than identical models that can run on gasoline only. (The switch to FFV requires only two minor upgrades: in the materials used in the fuel line and in the software controlling the electronic fuel injector.)

FFVs currently command only about 3 percent of the new-car market. After all, there is little upside for consumers to own one, with alcohol-fuel pumps being nearly as rare as unicorns. Little wonder: Why should gas-station owners dedicate one of their pumps to alcohol fuels (like E85 — a mix of 85-percent ethanol and 15-percent gasoline — or M50 — a mix of half methanol and half gasoline) when only a tiny percentage of cars can use them? But, within three years of the enactment of an FFV mandate, there would be 50 million cars on American roads capable of running on high-alcohol fuels. Under those conditions, fuel pumps dispensing E85 and M50 would be everywhere — creating, for the first time, an effectively open market in vehicle fuels, and competition for OPEC oil.

By mandating that all new cars sold in the U.S. have flex-fuel capacity, we would induce all foreign automakers who want access to the American car market to switch their lines to flex fuel as well, effectively making flex fuel the international standard. In addition to the 50 million FFVs we’d see in the U.S. in three years, there would be hundreds of millions more worldwide that could be powered by any number of alternative fuels derived from numerous sources around the globe, forcing gasoline to compete everywhere. This would effectively break the vertical monopoly that the oil cartel currently holds on the world’s fuel supply, constraining prices to the $50-per-barrel range (where alcohol fuels become competitive). "

This is a govt. regulation I could agree with. Better than most they come up with!:p

a couple other things to note, 1:the corn that is used for ethanol production is animal feed grain corn, I'm sure that you dont eat that, and then the byproduct from from producing ethanol is used to feed animals, not much of a loss there, getting two uses from one item. 2: beer companies are now putting theire waste product into ethanol production

anyhow, today the price for e85 is 2.89 USD while regular is 3.85 USD sounds like a fair traidoff even if you lose a couple mpg.

The corn used for animal feed is also used in a vast amount of consumer food products. While we eat sweet corn, the dimpled stuff is what gets turned into HFCS. Food is cheap because HFCS is cheap.

I think the real issue is unsustainable farming practices. The Ogallala water table is being quickly depleted, excess nitrates and other nutrients are creating dead zones in the Mississippi Gulf, and virgin land is being cleared to support an industry that can't possibly hope to make a dent in energy use.

Based on the amount of water, energy, and land needed to grow crops, biofuels will be nothing more than a tiny piece of the energy collage. It'll make a few rich farmers richer, though.

- LostCause