Why is Ethanol such a polarizing topic?

[cRiPpLe_rOoStEr]

Originally Posted by radioranger

anyone ever work with methane, it bubbles up everywhere from ponds etc, I know it;s hard to handle though .

Methane is the main component of CNG. If you wouldn't compress it, could still use as a vehicle fuel but the range would be quite limited. Have you never seen pictures of cars running on gaseous fuels stored in fabric-reinforced rubber bags in Europe during WWII, or Chinese buses running on this system until mid-90s?
Low-tech Magazine: Gas Bag Vehicles

I might admit I would like to try that for fun if I were a farmer with a constant and free methane supply

[radioranger]

I guess it,s a greenhouse gas so would kill two birds with one stone, if thats what theire after. my guess though is they just want less cars on the road . funny thing is the emissions rules make or made cars last longer! especially fuel injection . lot less oil washed down from the cylinders.

[Allch Chcar]

I had forgotten about the power loss with CNG. Checkout the Honda Civic Gx, 20 fewer BHP and only available with automatic. I'm not up-to-date with the conversion costs for CNG but those tanks are pretty expensive. Then you have even shorter range than Ethanol and less power than Gasoline. Don't get me wrong, Natural Gas is great stuff. It's cheaper than Gasoline and we produce plenty of it domestically. But look at this and this comparison.

The MPG difference between Gasohol and E85 is shrinking. Regular is increasingly 84 AKI Blendstock and 10% Ethanol to make AKI 87. E85 has about 72% of the energy of Indolene which is Pure Gasoline. But E85 has 75%(74.45% TBME), E75 is 78%, and 79% of the energy per gallon of Gasohol. I'm guessing the difference is +-1% between 87 and 89 AKI, based on Premium being 3% more efficient than Regular(given an appropriate engine).

[gone-ot]

Allch Chcar -- re: "...an appropriate engine..." The rapidly increasing use of turbocharged engines (ie: variable compression-ratio) can overcome the HP differences between straight-gasoline (indolene) and ethanol-laced mixtures (E85, etc.) but they will NEVER overcome the MPG losses because the energy content differential is too great.

Octane (knock resistance) is totally different from energy content (BTU).

[RedDevil]

But energy content, though the main factor, is not the only thing at play.

Ethanol will produce slightly more gaseous molecules in burning, so although the temperature would not rise as much as when burning pure gas, this is compensated slightly by the higher volume.
In other words, an ethanol mixture would convert less of its energy to heat and more to power, and even though the power produced will be less in absolute terms, its relative efficiency is slightly higher; you get more bang per BTU.
If your engine is hot enough by itself.

I would not be surprised if engines that have EGR (which adds a lot of heat) generally handle ethanol blends better than engines that do not have EGR.

Apart from that, high octane allows a more aggressive ignition timing and therefore better economy.
Of course, if you mix real bad gas with ethanol to arrive at an average total octane number, there is no positive effect. But if you used the same gas without the ethanol and take the octane hit with that, the FE might even be worse.
It would be unfair to blame the ethanol, the culprit is the bad gas that gets mixed in.

[Allch Chcar]

Teleman, it's been a proven fact for a long time that Ethanol makes more power even in traditional "Gasoline engines." It would be foolish mistake to claim Gasoline could ever approach Diesel levels of efficiency due to differences in engine design alone. Why are certain people insisting that Ethanol must do the impossible now to be competitive? Isn't it good enough that E85 is ~5% more efficient in flex fuel engines that are designed for Regular Gasoline?

BTW, Ethanol has been used in Compression ignited and Spark ignited engines. It has higher octane at Stoichiometric levels but at super lean mixtures it ignites much easier.

Things are changing and letting lower range continue to be an issue, is misguided short term thinking at best. Standard fuel tanks are already more than generous when manufacturers can claim 500+ miles between fillups. SUVs often have closer to 250 miles range if driven around town.

[gone-ot]

Originally Posted by Allch Chcar

Why are certain people insisting that Ethanol must do the impossible now to be competitive?

Because Ethanol (alcohol diluted gasoline) is nowhere nearly as energy 'dense' as pure gasoline (indolene), ie: a gallon of E85 does not go as "far" as a gallon of gasoline will.

Originally Posted by Allch Chcar

Isn't it good enough that E85 is ~5% more efficient in flex fuel engines that are designed for Regular Gasoline?

Sorry, but my data indicates that "Flex" engines not incorporating turbochargers (to yield variable-compression ratio operation) have been LESS efficient...only those engines capable of operating at higher CR can effectively "use" the higher octane value of E85 and so advance timing to produce more HP...but NOT better fuel economy, ie more distance per gallon.

Originally Posted by Allch Chcar

BTW, Ethanol has been used in Compression ignited and Spark ignited engines.

True in "short-duration" operation for diesels (CI), but not under continued long-duration operation because gasoline/alcohol 'solvent' is damaging to injectors, because the injectors rely on diesel for lubrication...which E85 lacks. The new gasoline direct-injection (GDI, SIDI, etc.) engines will 'test' the quality & durability of new piezo-injectors with gasoline AND E85.

Originally Posted by Allch Chcar

It (ethanol) has higher octane at Stoichiometric levels but at super lean mixtures it ignites much easier.

Current EPA regulations effectively dictate SI "closed-loop" engine operation at stoichiometric (~14.7:1 A/F) because of the catalytic convertors; hence, the days--and discussions--of "lean-burn" operation is meaningless.

Originally Posted by Allch Chcar

Things are changing and letting lower range continue to be an issue, is misguided short term thinking at best. Standard fuel tanks are already more than generous when manufacturers can claim 500+ miles between fillups.

At one time the industry 'standard' was 8-hours driving at 50 mph, or 400 mile range, per tank...with tank "capacity" being 'sized' to achieve that range (roughly). Today, the 'standard' is more like 8-hours at 65 mph, or 520 miles expected range. And, since "fuel" is sold by volume, it isn't surprising that some people WANT as much range from each gallon they pay for as possible. It's called being 'conservative/frugile' rather than being 'extravagant/wasteful.'

[Frank Lee]

It's called being 'conservative/frugile' rather than being 'extravagant/wasteful.'

So that's why the roads are populated with SUVs going 80 mph?

At any rate, the frugal part of Frank Lee hearts ethanol; with E10/E85 blends I notice little to no degradation of mpgs AND the E85 price break completely and unequivocably lowers my cost per mile. And even on straight E85 (keep in mind I don't own ANY flex fuel vehicles) with the sometimes quantifiable mpg drop it still costs less per mile. Ex: last time I drove the F150 pulling the flatbed it got 16 mpg on a tank of 100% E85. It is unusual for the F150 to achieve 16 mpg towing no matter what grade of fuel is used.

[gone-ot]

Originally Posted by Frank Lee

So that's why the roads are populated with SUVs going 80 mph?

Sorry, Frank, I can't speak for the other idjiots on the roads, only this idjiot (me)!

[Frank Lee]

What about the rest of what I said?