The Great Ethanol Ripoff

June 21, 2010 9:36 AM

Ethanol Industry Takes Advantage of Gulf oil spill. The blowout of BP's Macondo well has given the corn-ethanol industry yet another opportunity to push its fuel adulterant on the American consumer. And unfortunately, the Obama administration appears ready and willing to foist yet more of the corrosive, environmentally destructive, low-heat-energy fuel on motorists.

Yes, it's madness....Earlier this year, the Earth Policy Institute estimated that in 2009, the U.S. ethanol industry consumed 107 million tons of grain, or about 25 percent of total domestic grain production. That amount of grain, said the Institute, "was enough to feed 330 million people for one year at average world consumption levels."...

posted by storybored (52 comments total)

First of all, starvation in the world is not the result of there being too little food in the world. Trivial proof: Obesity. If anything, driving up the price of corn would make Americans at least healthier and would do nothing to starve anyone else.

Second of all, not all ethanol is corn ethanol. Ethanol doesn't even necessarily require *land* (think algae) let alone corn. It's a great idea for multiple reasons, from diversity (you can make ethanol from lots of different sources) to sustainability (duh) to simplicity (you can make it at home).

And don't give me that nonsense about "but $X won't produce enough energy to cover all of $A, $B and $C!". It doesn't have to. Every drop of oil saved is a drop of oil saved. Solving part of the problem is an absolute good, especially if we have multiple partial solutions.
posted by DU at 9:44 AM on June 21, 2010 [2 favorites]

The real issue with ethanol isn't so much the food that it might have been. The US produces more corn than anyone can find uses for. Our entire agribusiness is structured around fracturing corn into molecular components and then recombining those into food shaped things. The fact that it isn't made available to hungry people is an issue of politics not scarcity.

The hidden downside of corn ethanol is that the the fertilizer required to raise massive mono-cultures of corn at high speed uses more fossil fuel than the ethanol produced can replace. The first couple chapters of Michael Pollan's Omnivore's Dilemma are an eye-opener.
posted by Babblesort at 9:45 AM on June 21, 2010 [23 favorites]

DU, the the ethanol infrastructure in the USA is corn based, as far as I can tell there is no movement to change this.
posted by kuatto at 9:47 AM on June 21, 2010 [1 favorite]

DU: are your comments based on the article or on the [more inside]? The article makes it pretty clear that ethanol damages vehicles & other gas-powered tools and increases air pollution. How is that an absolute good?
posted by Saxon Kane at 9:50 AM on June 21, 2010

If anything, driving up the price of corn would make Americans at least healthier and would do nothing to starve anyone else.

But we could that a lot more cheaply by simply ending government subsidy programs for corn farmers, which we spent $4 billion on in 2009 alone. We also paid out $1.7 billion in 2009 for soybean subsidies, which generally goes to the same companies, which tend to use corn and soybeans in rotation.

Our farm subsidies are absurd across the board, though. Shoot, in 2009 we gave $202 million to tobacco farmers! Talk about shooting yourself in the foot.
posted by jedicus at 9:52 AM on June 21, 2010

treehugger has a handy post comparing biodiesel to ethanol - I feel pretty strongly that biodiesel is the most logical in-between stage in moving off of petroleum
posted by zenwerewolf at 9:52 AM on June 21, 2010 [1 favorite]

the problem with bio-fuels in general is deforestation.
posted by bhnyc at 9:54 AM on June 21, 2010 [1 favorite]

My short Ethanol Story:

Without giving too much away: I met with Ethanol reps looking for private investors about 2 years ago. The returns they promised were insane; not like "this is a great deal!" more like "this is obviously some kind of ponzi scheme". They also promised us referral bonuses that were way out of line with comparable proposals and were guaranteed to increase even year.

I asked them what would happen if the Federal subsidies were diminished or eliminated and they told me that the subsidy will not be eliminated any time soon (which I believe) and that even if it were, ethanol would still be highly profitable (which I do not).

I prepared a bunch of follow-up questions I thought would likely come up from potential investors and received unsatisfying answers, although they did try to get us to sign an exclusivity arrangement.
posted by 2bucksplus at 9:57 AM on June 21, 2010 [1 favorite]

In addition to problems with their cars, consumers may soon find that more ethanol in their gasoline will result in the fouling of smaller engines.

Terrible Engines Terrible, Film At 11. If you are running a two-stroke engine, you are killing the Earth. If that two-stroke engine (or your car) is so hopelessly out of date that it isn't safe from ethanol, all the more reason to remove it from operation.

The claim about increased air pollution from ethanol links to an EPA report, which says this:

At the same time, other vehicle emissions may increase as a result of greater renewable fuel use. Nationwide, EPA estimates an increase in total emissions of volatile organic compounds and nitrogen oxides (VOC + NOx) between 41,000 and 83,000 tons. However, the effects will vary significantly by region. Areas that already are using ethanol will experience little or no change in emissions or air quality. However, those areas that experience a substantial increase in ethanol may see an increase in VOC emissions between 4 and 5 percent and an increase in NOx emissions between 6 and 7 percent from gasoline powered vehicles and equipment.

I don't get that at all. Because of nitrogen in ethanol? Or because of ethanol + gasoline?

Anyway, that entire article reads like it was written by BP.
posted by DU at 9:57 AM on June 21, 2010 [1 favorite]

I think, personally, if we were going to go down the route of alcohols methanol would be a more sensible alternative. Simply because it is easier to make methanol by gasification than it is to make ethanol by the same route, and gasification opens up new sources of biomass that aren't available for conventional fermenting and distilling.

Overall, though, there are lots of different kinds of biofuels being tested out and corn based ethanol is by far the least promising.
posted by selenized at 9:59 AM on June 21, 2010

Corn-based ethanol is not a great idea, absolutely. Ethanol-of-some-kind, though, is a pretty good one. I find the combination of DIY-level simplicity and 99%-plug-in-replacement (i.e. you can almost certainly use ethanol in the car you currently drive with zero infrastructural change) to be a big win.
posted by DU at 10:03 AM on June 21, 2010 [1 favorite]

> If anything, driving up the price of corn would make Americans at least healthier and would do nothing to starve anyone else.


The corn grown for ethanol is not fit for human consumption. But, we should just import the sugar based ethanol from Brazil, minus the gregarious tariffs.
posted by Burhanistan at 10:06 AM on June 21, 2010 [1 favorite]

gregarious tariffs

Tariffs do tend to come in groups, but I wouldn't normally regard them as gregarious. Now, egregious I could believe.
posted by jedicus at 10:10 AM on June 21, 2010 [1 favorite]

DU: what about ethanol's low energy density and the fact that it is very hygroscopic, so picks up water which rusts fuel tanks and has to be driven off energetically?
posted by henryaj at 10:11 AM on June 21, 2010

Ah! damn Firefox spellchecker! Of course, outlandish, egregious, etc...
posted by Burhanistan at 10:12 AM on June 21, 2010

The hidden downside of corn ethanol is that the the fertilizer required to raise massive mono-cultures of corn at high speed uses more fossil fuel than the ethanol produced can replace.

Mechanically tilling the soil the corn is grown on also releases masses of carbon dioxide from the soil itself, further adding to the net positive carbon emissions of bioethanol.
posted by henryaj at 10:13 AM on June 21, 2010

I don't get that at all. Because of nitrogen in ethanol? Or because of ethanol + gasoline?

At least as far as the vocs go I would hazard a guess that it is a blending issue. While ethanol has a low rvp on it's own, when blended with gasoline the rvp of the mixture is higher than straight gasoline. I've been told that the vapour pressure of the gas is a key factor in vocs.
posted by selenized at 10:21 AM on June 21, 2010

Ethanol is the only thing that's helped me deal with this oil spill so far.
posted by GuyZero at 10:26 AM on June 21, 2010 [4 favorites]

Did you hear the new Gregarious Tariffs album? It explores new territory, but I found it rather taxing.
posted by swift at 10:33 AM on June 21, 2010 [3 favorites]

The claim about increased air pollution from ethanol links to an EPA report

There's also the Stanford study on E85 pollution (PDF) if you're interested. Seems ozone and acetaldehyde are the potential culprits.
posted by RobotVoodooPower at 10:34 AM on June 21, 2010

If you are running a two-stroke engine, you are killing the Earth. If that two-stroke engine (or your car) is so hopelessly out of date that it isn't safe from ethanol, all the more reason to remove it from operation.

Yeah, fuck poor people. It's their fault the earth is burning!
posted by Pope Guilty at 10:43 AM on June 21, 2010 [4 favorites]

The corn grown for ethanol is not fit for human consumption.

Most corn grown in the U.S. is not fit for human consumption, at least not directly. It is grown specifically and almost solely for one of two purposes: (1) animal feed, (2) a feedstock / raw ingredient for industrial processes which may or may not produce food. The latter includes the production of corn starch, corn syrups, etc.

I've been told from people who grew up on corn farms that you can eat field corn if you are really hungry, but it tastes very, very bad -- starvation food, basically. I think the shortest route to palatability involves soaking it in wood ash (lye) in order to make hominy.

Of course, wheat isn't really that edible straight off the plant either, so I'm not sure this is the best criticism of modern corn-based agriculture -- there are much better ones IMO.

The problem I have with corn-based ethanol is the topsoil and deep groundwater depletion as a result of industrial farming. It makes no sense to replace a nonrenewable resource with an even more dear nonrenewable (on human timescales) one.

That said, cellulosic ethanol seems like it has some promise, so it doesn't seem like a bad idea to mandate that all cars be able to tolerate ethanol fuels. The subsidies, however, are insane.
posted by Kadin2048 at 10:54 AM on June 21, 2010 [2 favorites]

> Of course, wheat isn't really that edible straight off the plant either, so I'm not sure this is the best criticism of modern corn-based agriculture -- there are much better ones IMO.

Agreed, but I was responding to the suggestion that "driving up the price of corn would make Americans at least healthier and would do nothing to starve anyone else."
posted by Burhanistan at 10:57 AM on June 21, 2010

DU: “Anyway, that entire article reads like it was written by BP.”

The benefits of ethanol aside, this is bullshit. BP loves ethanol. Ethanol is in large part the baby of the oil companies; they've been cheering it on and giving it as much support as they can from the start.

If a lot of us are instinctively wary of the whole idea of ethanol, it's mostly because it's the oil companies that are trying to sell it to us.
posted by koeselitz at 11:33 AM on June 21, 2010

One of the main reasons why ethanol is so successful in Brazil is that sugar cane ethanol is so efficient (and the government has been pushing it heavily for years and years).
The cost/vs efficiency ratio means that corn-based ethanol costs almost exactly the same at the pump as regular unleaded gas (at least in Portland, OR), but with the added hidden cost of deep subsidies.
Algae-based biodiesel is really the way to go. It seemingly grows on air and sunlight and doesn't involve supplanting edible corn for inefficient inedible corn.
posted by tmt at 11:49 AM on June 21, 2010 [1 favorite]

First of all, starvation in the world is not the result of there being too little food in the world. Trivial proof: Obesity.

This is not a proof. A few fat people (relatively speaking, looking at the world population) among a large crowd doesn't imply that there's enough food to go around. Obesity implies that food supplies are concentrated geographically, but says little, directly, about overall quantity itself.

Second of all, not all ethanol is corn ethanol.

In the United States, most ethanol is derived from corn.

Ethanol doesn't even necessarily require *land* (think algae) let alone corn.

Algae is being researched. We're not there yet.

Every drop of oil saved is a drop of oil saved. Solving part of the problem is an absolute good, especially if we have multiple partial solutions.

If ethanol rots a car's innards out faster than it is replaced, oil used to replace parts sooner are drops lost.

I don't get that at all. Because of nitrogen in ethanol? Or because of ethanol + gasoline?

There are strong arguments on both sides of the debate over whether ethanol use raises, lowers or leaves emission levels unchanged. How do ethanol blends change basic combustion properties? If ethanol or an ethanol blend lowers a car's mileage, and the driver has to make more frequent trips to the gas station for the same miles, does this raise overall emissions even if ethanol by itself burns cleaner? It still remains an unresolved question.
posted by Blazecock Pileon at 11:52 AM on June 21, 2010 [1 favorite]

Corn is for drinking, not for burning: corn stoves

If you didn't know about these, it may seem very strange.
posted by warbaby at 11:55 AM on June 21, 2010

Also, if I'm going to throw my own opinion into this:

New technologies for fuel are neat. New technologies for fuel mean almost nothing until we actually implement the technology we have.

It's entirely possible to make normal cars exactly like today's cars that get 150-200 mpg if you just put hybrid diesel engines in them.

The fact that no one's done this - and that the only hybrids available now get less mpg than many turbodiesels - is an indication that nothing is going to change. Ethanol is two things: first, they get to get lots of money from the government for it, and they charge us a lot at the pump, too; second, it's an experiment, because certain powers that be are hopeful that they can keep people chained to the model of having to buy fuel at the same outlets. "Certain powers" are the oil companies. Ethanol is just the oil companies' way of making some money off of us while trying to ensure that we're always in their thrall.
posted by koeselitz at 11:56 AM on June 21, 2010 [2 favorites]

Little airplanes can't burn ethanol in their piston engines. General aviation mostly uses 100 low lead gas; not unleaded, "low lead". There's a big EPA push to switch to unleaded. And in fact, many planes can burn ordinary unleaded car gasoline. Except it has to be pure gasoline, no ethanol added. And it's pretty much impossible now to buy pure gasoline; it's all been adulterated with ethanol. So we're stuck burning lead instead.

The real problem with piston airplanes is that the engine technology is 50+ years old. If it weren't for regulation and liability insurance we could be 20-50% more efficient with fuel.
posted by Nelson at 12:07 PM on June 21, 2010

I live near the largest concentration of corn ethanol plants that I know of, near Cedar Rapids, Iowa. It is pretty much the world center for production of breakfast cereals, but many of those plants are now making big money now producing ethanol from corn. It's a huge boondoggle, it's corporate welfare since the money is all going to big corporations like Archer Daniels Midland, who made their agribusiness fortunes producing high fructose corn syrup. This whole ethanol business makes me sick. Really. If you go to Cedar Rapids, you will smell the sickening stench of boiling grains, it turns my stomach.

Ethanol production is a net energy loss, it takes more energy to produce it than it releases when used as fuel. It's terribly inefficient in all regards, and isn't sustainable. It can't be shipped to the end users via pipeline, so it has to be carried in railroad tankers, transported by locomotives that don't run on ethanol. I hear endless trains running 2 blocks away from my house, every night. It takes a massive amount of electricity to process the corn into ethanol, and ethanol is too inefficient to power the methanol production facilities. So where does that energy come from? The local nuclear energy plant about 10 miles away. They are using nuclear energy to make ethanol. Does something sound wrong with this process?
posted by charlie don't surf at 12:34 PM on June 21, 2010 [2 favorites]

They are using nuclear energy to make ethanol. Does something sound wrong with this process?

Not necessarily. Taking a net loss in energy to convert electricity into liquid fuels (so that our existing oil-based infrastructure can run on electricity) may be worthwhile if it results in less oil use, but OTOH, it also reduces the incentive to build the necessary non-oil-based replacement infrastructure, which might be a bigger problem over the long-term.
posted by -harlequin- at 12:41 PM on June 21, 2010 [1 favorite]

Does something sound wrong with this process?

Not really. The fuel is essentially a disposable battery. They were considering building a nuclear plant to power the energy-intensive oil sands extraction plants in Alberta. Crazy, but by no means the craziest.

It's a heck of a lot safer than just putting a nuclear fuel cell into every car.
posted by GuyZero at 12:44 PM on June 21, 2010

Oh. P.S.

In midst rant, I forgot to add my postscript. I will never use gasohol. I bought it once by accident, back in the 80s when they were first experimenting with it. I accidentally filled the tank of my beautiful 1965 Mustang GT convertible. The owner's manual actually recommended the high-compression 289 engine use 110 octane gas (almost jet fuel grade) which was unobtainable even in the 80s. It took a bit of fine tuning to get it to run well on lower octane gas.

OK, so it was winter, and very cold temperatures caused the alcohol and gasoline to separate. So I'm cruising down the interstate and one minute, I'm burning pure gas, and then the next moment, I'm burning pure ethanol, and BOOM I've got blown gaskets and a cracked engine block. The End for my beautifully restored Mustang, the engine block was irreplaceable. Curse you, damn ethanol, for destroying the best car I ever owned.
posted by charlie don't surf at 12:44 PM on June 21, 2010 [1 favorite]

It's a heck of a lot safer than just putting a nuclear fuel cell into every car.

Well, my point was, it would be a lot safer and more efficient to just make electric powered cars that run off batteries, fueled by the nuclear power plant. The intermediate steps of ethanol production just introduce more losses by inefficient conversions.

But still, people have designed nuclear powered cars, like the Ford Nucleon. It makes sense from an energy efficiency viewpoint, but that's about all that makes sense.
posted by charlie don't surf at 12:50 PM on June 21, 2010

The owner's manual actually recommended the high-compression 289 engine use 110 octane gas (almost jet fuel grade)

It is a common misconception that 'jet fuel' has a high octane rating. In fact, jet fuel is kerosene-based and very similar to diesel fuel, which has a very low octane rating. Fuel used in piston aircraft (avgas), however, does sometimes have a high octane rating (as high as 145), but in general it is actually pretty similar to normal automotive gasoline, at least in terms of octane rating.
posted by jedicus at 12:59 PM on June 21, 2010 [3 favorites]

If you don't want to pay for corn ethanol, you can brew your own ethanol at home from pretty much any starchy fruit or vegetable, or even from agricultural waste such as corn stalks.
posted by ekroh at 1:03 PM on June 21, 2010

Well, my point was, it would be a lot safer and more efficient to just make electric powered cars that run off batteries, fueled by the nuclear power plant.

Unfortunately for now batteries have a lot lower energy density than liquid fuel, so it's not really that much more efficient. Also, what energy you lose in the conversion process of ethanol you partially recoup in being able to stick the ethanol plant beside the nuclear plant and not having all those high-voltage transmission losses.
posted by GuyZero at 1:07 PM on June 21, 2010

I laugh at all the E85 suckers on the roads today. "Oh, it's so cheap!" Until you factor in the lower fuel efficiency versus pure, delicious gasoline. My kingdom for a nuclear-powered electric car infrastructure.
posted by cellphone at 1:22 PM on June 21, 2010

"They were considering building a nuclear plant to power the energy-intensive oil sands extraction plants in Alberta."

They still are considering it last I heard. The recession may have put a temporary damper on capital-intensive projects, but enthusiasm for a nuclear powered oilsands will probably take off again when the economy shifts back into high gear. From a government prospective, nuclear power plants and ethanol production are great things because they put money in the right pockets, while paying lip service to environmental protection. I've nothing against the idea of government subsidies, but it would make more sense to put them into industries like solar power than ethanol.
posted by Kevin Street at 2:28 PM on June 21, 2010

Unfortunately for now batteries have a lot lower energy density than liquid fuel, so it's not really that much more efficient. Also, what energy you lose in the conversion process of ethanol you partially recoup in being able to stick the ethanol plant beside the nuclear plant and not having all those high-voltage transmission losses.

Well, the ethanol still has to be shipped to users via railroad so making it near the nuclear plant doesn't really make it much more efficient overall. And the low energy density of batteries doesn't make them inefficient, it just makes them any given mass of batteries capable of moving you a shorter distance than the same mass of gasoline. This is all a bunch of tradeoffs.
posted by charlie don't surf at 2:35 PM on June 21, 2010

DU : Terrible Engines Terrible, Film At 11. If you are running a two-stroke engine, you are killing the Earth. If that two-stroke engine (or your car) is so hopelessly out of date that it isn't safe from ethanol, all the more reason to remove it from operation.

Sorry, but "no".

If you go out today and buy a top-of-the-line 4-stroke lawnmower that doesn't specifically say it will run on E85 (Amazon lists zero of them), then the ethanol in your typical E90 highway-grade gasoline will rot out the rubber and most plastics pre-ignition, and most metals post-ignition (including the cylinder itself).

I fully support alternative fuels, and would even stand behind a mandate to require all gasoline engines sold from now on qualify as FFVs. But this BS of quietly boosting the ethanol content in all standard commercially-available gasoline without making sure most engines can use it first? How much do you think it will help save the planet to drop the average lifetime of a lawnmower from over a decade to 2-3 years?
posted by pla at 3:49 PM on June 21, 2010 [1 favorite]

My 62 Buick runs great on E85. I can't afford a new hybrid and I love my old car so I made the switch. It wasn't very hard to do and E85 is equivalent to 104 Octane and a lot cheaper than racing gas.
posted by ambulocetus at 7:16 PM on June 21, 2010

"what about ethanol's low energy density and the fact that it is very hygroscopic, so picks up water which rusts fuel tanks and has to be driven off energetically?"

It works the other way around. Ethanol mixes with both gasoline and water preventing water from accumulating in your sealed gas tank. It's how gasline antifreeze works (though usually with cheaper methyl hydrate) Besides, most new gas tanks are plastic which won't rust and they have recirculating in tank pumps which keeps everything well mixed even if they were prone to separation.

"I accidentally filled the tank of my beautiful 1965 Mustang GT convertible. The owner's manual actually recommended the high-compression 289 engine use 110 octane gas (almost jet fuel grade) which was unobtainable even in the 80s. It took a bit of fine tuning to get it to run well on lower octane gas."

I've never heard of a street engine requiring 110 octane gas, not even 10.5:1 engines like the HO289 available in 65.

"OK, so it was winter, and very cold temperatures caused the alcohol and gasoline to separate. So I'm cruising down the interstate and one minute, I'm burning pure gas, and then the next moment, I'm burning pure ethanol, and BOOM I've got blown gaskets and a cracked engine block. The End for my beautifully restored Mustang, the engine block was irreplaceable. Curse you, damn ethanol, for destroying the best car I ever owned."

I've never heard of gasoline separating from alcohol from the cold. I'm not even sure what the mechanism would be because it sure wasn't freeze distillation (ethanol freezing point is around -100). However it is likely that that moisture in your tank/gas froze in your carb and caused your mixture to lean out resulting in knock and detonation.

Even if your blown engine was caused by gasoline and ethanol somehow separating (and not getting mixed together in your fuel filters and bowls) the ethanol has a higher octane rating than gasoline and wouldn't have caused your detonation.
posted by Mitheral at 7:44 PM on June 21, 2010 [2 favorites]

I've never heard of a street engine requiring 110 octane gas, not even 10.5:1 engines like the HO289 available in 65.

Well, it wasn't required, it was recommended. I recall once finding 104 octane gas and my car drove like a dragster. With hi-test gas, you could actually get it to put out more than 289hp. The only other 1965 engine that I know of that could put out more hp than it had cu. in was the Mopar 426 Hemi, which could put out 433hp.

I've never heard of gasoline separating from alcohol from the cold. I'm not even sure what the mechanism would be because it sure wasn't freeze distillation (ethanol freezing point is around -100). However it is likely that that moisture in your tank/gas froze in your carb and caused your mixture to lean out resulting in knock and detonation.

This is a well known problem with gasohol. It was a huge fiasco the first winter gasohol was on sale, they hadn't figured it out yet. That was when I ran into the problem.

It's not the low temps that makes it separate, it's the presence of water condensation caused by low temps. Water can condense in the gas tank in very cold weather, and the ethanol promotes this since it is hygroscopic. Ethanol is soluble in water or gasoline. But water is insoluble in gasoline, so it would make the ethanol/water solution separate and sink to the bottom of the tank. And of course, the fuel lines draw fuel from the bottom of the tank. Check out page 19 onward in this PDF file for a description and testing of this problem.

Even if your blown engine was caused by gasoline and ethanol somehow separating (and not getting mixed together in your fuel filters and bowls) the ethanol has a higher octane rating than gasoline and wouldn't have caused your detonation.

The HiPo 289 wasn't designed to operate on a methanol/water mix, and even if it was pure ethanol, that's 129 octane and that is way too much for a high compression V8 built for the street.
posted by charlie don't surf at 12:20 AM on June 22, 2010

Oh, I just caught this..

My 62 Buick runs great on E85. I can't afford a new hybrid and I love my old car so I made the switch. It wasn't very hard to do and E85 is equivalent to 104 Octane and a lot cheaper than racing gas.

Yeah, but you've got another problem. Those old cast iron engines were designed to run on leaded gas. The original valve seals will corrode when used with unleaded gas, and it is a serious problem in older engines. I passed on restoring my old '65 Cuda when I discovered how expensive it was to have the old "soft" valve seats machined out and new hardened seats installed.

To prevent this problem, for a while after leaded gas was discontinued, you could buy bottles of lead additive. But the EPA stopped that pretty quickly.
posted by charlie don't surf at 12:37 AM on June 22, 2010

driving up the price of corn would make Americans at least healthier and would do nothing to starve anyone else

Corn is a fungible commodity, so the price would go up everywhere. In fact, it already has; see the Washington Post in 2007: "Mexico is in the grip of the worst tortilla crisis in its modern history. Dramatically rising international corn prices, spurred by demand for the grain-based fuel ethanol, have led to expensive tortillas. That, in turn, has led to lower sales for vendors such as Rosales and angry protests by consumers."
posted by mcwetboy at 7:47 AM on June 22, 2010

There seems to be a common misconception in this thread that gas Octane Rating has something to do with the energy content of the fuel. This is false. The gasoline companies make a lot of money of this myth, so they promote it.

Higher octane gas is more resistant to auto-ignition from high temperature/compression. If the fuel in an engine cylinder ignites at the wrong point in the cycle, it makes a loud "knocking" noise and will push the wrong direction against the camshaft causing a sudden drop in engine power. This is not a subtle effect. If you've never experienced it before you'll think your engine has blown out. So if an engine (any engine) is not knocking, then it does not benefit from higher octane gas. Engines designed to use higher than normal compression levels require higher octane gas in order to avoid knocking, not to gain a power advantage.

Different octane-grades of gas are mostly the same stuff, but with different levels of additives in them to increase their knock resistance. The old, traditional way of making knock-resistant gas was to mix in something cheap with a high specific heat rating: lead.

Ethanol does have a reasonably high knock resistance rating (as listed in the wikipedia chart). But it contains less chemical energy than standard gasoline. So if more ethanol is added to your gas, then your millage will decline. Just one of the many levels on which the ethanol fuel industry is a scam.
posted by dodecapus at 8:02 AM on June 22, 2010

Bonus cite: http://wikimedia.org/wikipedia/en/wiki/Heating_value
Ethanol contains only 60% of the heat energy of gasoline by mass. Ethanol is more dense than gasoline, but even adjusting for that, it's only 66% of the energy of gasoline by volume.
posted by dodecapus at 8:15 AM on June 22, 2010

Meanwhile, in the wonderful world of natural gas:

The Costs of Natural Gas, Including Flaming Water

Gasland: Will New York Be the Next Casualty of the Halliburton Loophole?

Daily Show interview with Josh Fox
posted by homunculus at 8:56 AM on June 22, 2010 [1 favorite]

Sorry Charlie, my engine was freshly re-built with modern gaskets and hardened valve seats. I did my research and I haven't had even the tiniest problem. (By the way, my block is aluminum)
posted by ambulocetus at 3:40 PM on June 22, 2010

"Those old cast iron engines were designed to run on leaded gas. The original valve seals will corrode when used with unleaded gas, and it is a serious problem in older engines. I passed on restoring my old '65 Cuda when I discovered how expensive it was to have the old "soft" valve seats machined out and new hardened seats installed. "

Non hardened seats in either of the slant sixes or the baby LA will last 30-40K if they have had significant use running leaded gas before going to unleaded. Getting the seats changed adds less than a $100 to the cost rebuilding the engine even in the solid lifter Commando trim. And it's not even something that needs to be done right away; I never did when switching over to (unleaded) propane. Dodges are pretty forgiving on this score; you wait until it starts missing at all RPM levels and then you get the heads done.

"The HiPo 289 wasn't designed to operate on a methanol/water mix, and even if it was pure ethanol, that's 129 octane and that is way too much for a high compression V8 built for the street."

Too high of an octane rating doesn't hurt your engine. Long term I've heard it can cause carbon deposits but I've never actually seen that.
posted by Mitheral at 5:25 PM on June 22, 2010

So if an engine (any engine) is not knocking, then it does not benefit from higher octane gas.

Not really true. My car is designed for high octane, but if you put low octane in it, the computers will register the shifting ignition point and adjust the engine cycle to avoid knocking. The engine won't be running as effectively, but it won't be knocking.
posted by -harlequin- at 1:10 AM on June 25, 2010