I heard a brief statement on the radio condemning ethanol because vast amounts of water are required to produce the stuff. Water tables near ethanol plants are being run to dangerously low levels. Has anyone heard about this?

 

I have, there are alot of downsides to increasing its production. They did drop the amount of energy required to produce it.

Its a stopgap product that should not be in anyone's long-term energy planning.

 

Its a stopgap product that should not be in anyone's long-term energy planning.

Here we go again, some of do not agree:
-Ethanol production uses less energy than oil production:http://www.usatoday.com/educate/lockheed/Ethanol.pdf

-E30 produces better fuel economy and less emissions than straight gasoline:
http://www.ecofriendlydriver.com/e20...wer-emissions/

- 10.1 million tons of C02 equivalent greenhouse gas emissions reduced through the use and production of 6.5 billion gallons of ethanol in 2007
http://www.ethanolrfa.org/resource/facts/environment/

And a lecture:
The "BTU adjusted price" is one of the most idiotic concepts ever foisted on the consumer. Fuel economy does not track with fuel energy (BTUs) per gallon. It tracks with engine efficiency. Since E85 is a superior fuel it produces more useful work per BTU of available fuel energy.
This is obvious even looking at commercial flex-fuel vehicle (FFV) fuel economy numbers. Some of the FFV's get fuel mileage losses compared to gasoline of about 15%-20% yet the fuel contains approximately 25%-27% less energy on a gallon for gallon basis. If AAA's BTU corrected price concept was valid, this would be impossible. So the question is, where did that extra 10% fuel efficiency come from? If we have a 25% energy deficit in the fuel and a 15% mileage drop, where did we get 10% more mileage than predicted?
It came from a superior engine setup and tuning, and taking advantage of the strengths of ethanol as a fuel to recover more useful work from the fuel. (See the math at the end of this article)
My current fuel cost for E85 is $2.99/gallon. I get about 19 mpg in daily driving. That means it costs me 15.7 cents a mile to use E85.
If I used pump premium, which my engine requires anyway, it would cost me $4.15 a gallon and I would get 22 mpg on gasoline. That means it would cost me 18.86 cents a mile.
Gasoline costs me 20% more per mile than E85, which for me comes to $750 a year.
AAA's adjusted E85 price is a derived number based on false assumptions.
AAA says:
"The BTU-adjusted price of E-85 is the nationwide average price of E-85 adjusted to reflect the lower energy content as expressed in British Thermal Units - and hence miles per gallon - available in a gallon of E-85 as compared to the same volume of conventional gasoline."
Let's start with the difference between fuel BTUs and fuel/engine efficiency. The fuel mileage per gallon available from a fuel is not tightly tied to its energy content per gallon. It is false to assume so, and this is widely known in the car community.
Fuel mileage is much more closely tied to engine efficiency and how well it makes constructive use of the available energy in the fuel. Since E85 has several characteristics that make it a more efficient fuel than gasoline, you get more useful work out of a given amount of available fuel energy using E85 than you can on gasoline. In highly optimized engines, fuel ethanol can achieve thermal efficiencies of 42% compared to about 30% for a well-designed gasoline engine on the streets today.
E85 and fuel ethanol actually have higher specific energy than gasoline, and can produce significantly more power for a given amount of air taken into the engine. In proper fuel-air mixtures E85 is capable of increasing an engine's power output from 5% to about 27% more than on pump gasoline.
Total available power from a fuel is determined by how much fuel you can burn with a given amount of intake air. In the case of E85, with the right fuel-air mixture, it blows gasoline away completely. Likewise at light throttle cruise, you can run E85 at much leaner mixtures without misfire due to its wider flammability limits, and still have normal torque for passing and accelerating up hills. That's because the fuel allows the engine to accept load at lighter throttle settings than you can get away
with on gasoline. Net result, is the driver needs less throttle and less fuel to cruise at a given highway speed and spends less time on high throttle for hills. This results in significantly better fuel mileage in the real world than the raw BTU content of the fuel would lead you to believe.
One commonly reported result of this difference is that drivers in hill country find that on E85 their cruise control seldom has any problems on the hills, where on gasoline in the same car, the cruise control is constantly struggling to accelerate to maintain speed up the hills. This is due to E85's ability to accept load with out laboring the engine.
This is no magic here, just simple physics. E85 consistently shows slight but noticeable improvements in mid-range torque in the critical rpm range where drivers spend most of their time when cruising. This means less throttle for passing and hill climbing and less need to downshift.
Below are the numbers from my first E85 conversion on a stock [Subaru] turbo.

stock turbo: Gasoline @116,090 Btu/gallon and 24mpg = 4,837 BTU/mile
conversion turbo: E85 @ 76,367 BTU/gallon and 22 mpg = 3,471 BTU/mile

That setup on E85 uses 72% of the fuel energy that gasoline uses to travel a mile. My current setup is a bit less efficient as I nowhave a larger turbocharger for more power (I am a performance guy after

all!) As you can see, there is very little lost in miles per gallon and a definite gain in absolute fuel efficiency (i.e. miles/BTU).
In states where the public is getting a fair price for E85, and the car is correctly tuned, it saves the driver a considerable amount of money.
Now if the commercial manufacturers would just produce a flex fuel vehicle closer to the efficiency that back yard tuners can produce in a couple of hours....
How is it that back yard mechanics consistently outperform the factories when it comes to FFV setups, frequently getting fuel mileages of 85%-90% of gasoline on E85?
First is a structural problem with the flex fuel concept. As the federal auto mileage standards are currently configured, the factory has absolutely no incentive to optimize the tune and engine performance for E85. They don't care if the cars get 12 mpg or 18 mpg on E85, because it's the gasoline mileage that matters for their mpg requirements (and they automatically get a big average mileage credit for the E85, no matter what the mpg on that fuel). Second, they are shaving every dime they can off car costs because of their tough competitive position.
In most FFV's the E85 ability is an afterthought. One of the critical differences between gasoline and E85 is the fuel octane. Regular gasoline has 85-87 octane while E85 has a rated octane of 105. The testing procedure used to measure octane is really not suitable for alcohol fuels as it forces the use of very high intake air temperatures that will simply never be seen in an E85 fueled engine due to the cooling effect of the alcohol. The real world road octane of E85 appears to be more closely comparable to a 112 octane gasoline.
So what does this mean to an engine designer? Engine knock or detonation is a malfunction in the combustion process that will literally destroy an engine if allowed to occur with any frequency. It is one of the key engineering constraints on the design of an internal combustion spark ignition engine.
Octane is a lab measurement that indicates a fuel's tendency to cause engine knock under load. High fuel octane fundamentally changes the engine design possibilities open to the engine designer.
Due to its high fuel octane E85 runs best (most efficiently - most useful work recovered from the fuel) in a high compression engine near 12:1
- 13:1 compression ratio. Common regular gasoline on the other hand is very limited in its ability to use compression ratios over about 9:1.
Unfortunately the physical compression ratio of an engine is set at the time of manufacture and cannot be changed "on the fly" with currently available
technology (at least not at a price you or I can afford).
That brings us back to the question of why back yard experimenters get better fuel efficiency than the factories. The simple answer is that they use E85 more effectively with simple techniques that vary the "effective" compression ratio of the engine. By using more aggressive ignition timing or using turbochargers as I do, they have an engine that can change its effective compression ratio to suit the fuel without major mechanical modifications.
For example, turbochargers are an ideal partner to E85 and the FFV concept. The effective compression ratio of the engine is the combined effect of the boost pressure generated by the turbocharger and the mechanical compression ratio of the engine itself. The beauty of the partnership is that it is very easy to change the turbocharger's peak boost pressure, so that when running E85 you have a high effective compression ratio, and when running regular gasoline you turn down the turbocharger boost so you have a lower operating pressure more suitable to the octane of conventional gasoline.
By doing that I was able to achieve fuel mileages on E85 near 90% of my fuel mileage on gasoline.
Bottom line is that the fuel mileage (CAFE) standard needs to be modified with some other incentive for the manufacturers to spend the extra couple hundred dollars a car to give the consumer an engine that is equally efficient on either gasoline or E85.
The other issue for owners is EPA emission rules. The Environmental Protection Agency needs to allow a method so car modifiers can opt out of the current process-based emissions system and buy into a performance-based emissions system. The current EPA regulations force all users to rigidly stick to the original factory engine configuration, yet experimenters easily pass even dynamometer-based emissions tests like the IM240 test on home conversion E85 cars.
The problem is that there is not practical method for owners of E85-modified engines to be in formal compliance, even though they have lower emissions than the car did when it came from the factory.
Let me pay the EPA $15.00 a year for an opt out, and I will happily emissions test my car every year. I will beat your factory emissions numbers, make more power and generate less greenhouse gases than my new car did, for an outlay of a few hundred dollars, instead of being forced to spend upwards of $20,000 to buy a new FFV for the pleasure of getting fuel mileage that sucks, higher insurance payments, higher registration and licensing fees and getting skinned by the loan company for the effort.
Process based emissions standards are obsolete! Let qualified people legally convert their cars to alternative fuels, and experiment with new options and concepts, and one of us will find a way to cut emissions and increase fuel efficiency at no cost to the government.

Gasoline vs. E85 efficiency:
An efficient engine uses the inherent strengths of a fuel. A typical gasoline engine needs to burn 0.5 lbs of gasoline an hour to produce one horsepower hour
of work. This is called the BSFC "brake specific fuel consumption".
If gasoline contains 18,766 BTU of energy per pound of fuel then the engine must burn 9,338 BTU of gasoline to produce one horsepower hour of work. A typical turbocharged engine running on E85 at light load will burn 0.65 lbs of E85 at 8,221 BTU/lb to produce that same horsepower hour of work. The turbocharged engine running on E85 needs to consume less fuel energy to do the same work. It does this by being more efficient at extracting work from the burning fuel.

 

Ok well good to know we still differ on opinions.

 

One thing I noticed right away and I posted about it months ago ( before reading that long but good article ) was my FEH ran at lower RPM on E85 and also that the RPM didn't go up at all on 2-3% hills with cruise control on.

Glad I'm not imagining this, or a victim of wishful thinking.

 

Not only is Exx cheaper and burn cleaner it also helps switch oil dependence from the mideast to the midwest

 

Hi,

Mostly I agree but I had to edit down the quote to separate data from advocacy. This is what I got from your posting:
I agree that on a cost-per-mile basis, fuel ethanol is a good buy and yes, the engine should be tuned for the higher octane. However, the Toyota and Ford hybrids use an Atkinson cycle and there are reports that the GM engine may have similar valve timing. In the case of the Prius:

• compression stroke: ~8-to-1
• expansion stroke: ~13-to-1

Our Atkinson engine efficiencies are already midway between a standard Otto and diesel. I've seen evidence that the Prius engine, probably the knock sensor, self-tunes for octane at higher power settings:

You'll notice that 93 octane fuel had similar specific fuel consumption to the ordinary gasoline. But at higher power settings, the engine does not back off the ignition timing as much and specific fuel consumption was slightly better. In my case, selecting a higher energy fuel makes most sense because ethanol is not available.

One other data point is these were hill-climb tests at an optimum fuel efficiency climb speed, 55 mph. In ordinary cruise, most of us like to keep the ICE rpm below 2,600 rpm (some like even lower rpm) to achieve 50-60 mpg cruise efficiency. It is just how our vehicles work.

Huntsville is one of those few pockets that have straight gas. The nearest ethanol seems to be at least a 1-2 gallon commute away so my ethanol experiments will wait. I don't fear ethanol but just wish we could reliably find retail ethanol at E30 or dependably, E85.

You've identified what I think is a real problem, we're all tied to "distance/fuel_volume" or "fuel_volume/distance" when the real measure should be "distance/$_currency." The cost per mile is a much better metric and takes the specific energy density out of the equation. You did an excellent job of pointing that out.

Bob Wilson