Ethanol in Your Gas by Roger Sitterly

Written for and distributed to the CIMC in February 2012. Since numerous non-CIMC MINI owners and Clubs have asked for this information, Roger is making the information available to all via this post. Copied without amendment, statements and opinions are his alone.

Ethanol in Your Gas

At the February 2012 club meeting, the subject of using “gasohol” (gasoline with ethanol blended into it) was raised. There is some serious debate about the wisdom of using ethanol-blended fuels in the engine of any modern automobile. The ethanol industry touts studies that show no evidence of damage to modern engines, and critics of the industry tout studies that show ethanol can and does cause sometimes extensive (and therefore expensive) damage to a car’s fuel system and/or engine.

I have assembled from various sources some basic information about ethanol-blended gasoline. Some of it is pretty simple and straightforward, some is a bit more complicated. I hope this will help everyone gain a better understanding of just what the discussion and controversy are about.

What is gasohol?

Most commonly, you will find “E-10” gasohol at service stations. That means the fuel you pump into your fuel tank can (and probably does) contain up to 10% ethanol by volume (the other 90% is supposed to be gasoline, but that is not always the case as will be shown below). Some “flex-fuel” vehicles sold today can use “E-85” fuel, which is supposed to contain up to 85% ethanol by volume (the other 15% is supposed to be gasoline).

An important point to keep in mind is that while Iowa (as well as probably all other states) regularly conducts tests on the accuracy of the dispensing pumps (to make sure you get 11.7 gallons of fuel when the meter says you’re being charged for 11.7 gallons of fuel), not one single state or other governmental entity is testing the quality of the fuel being dispensed. In other words, while you’re supposed to be getting no more than 10% ethanol when you pump E-10 fuel into your car, you could in fact be getting significantly more ethanol than you expect because there’s no quality check anywhere in the distribution system. It is possible to purchase a relatively inexpensive test kit that will enable you to determine the actual percentage of ethanol in any ethanol-blended fuel. I found a price range of between $30 and $50 in some quick on-line research, and those kits will perform up to 400 tests. The cost per test is therefore less than 25 cents, which might provide some inexpensive peace of mind for those who use ethanol-blended fuels in their cars.

Anecdotal evidence shows ethanol levels in E-10 fuel do sometimes significantly exceed the 10% stipulation. This most likely happens because ethanol is not added to fuel at the refinery; instead, it gets added at the local distributor level. According to David Redszus of Precision Auto Research, “The pump may say there is 10% ethanol in the fuel, but that can change every time the station’s tanks are filled, depending upon a variety of refining factors, including from whom the station buys its gas. You could be getting 10 percent, 12 percent, or even 15 percent, even at a name-brand station.” Distributors, Redszus says, “are supposed to add the right quantities of additives to the gas, but they may not have it dialed in.”

Excessive amounts of ethanol in what was being sold as E-10 fuel in the Dallas, Texas area is documented to have caused the following problem. A lady named Christi Jordan had a 2007 MINI that she took to Moritz MINI in Arlington for service. Her complaint was that it was difficult to start. Moritz’ mechanics inspected the car and found severe carbon buildup inside the engine. On a second visit, again because the car would not start, mechanics tested the ethanol content of the fuel in her car’s tank and found it “much higher than the federally-mandated limit of 10%.” The mechanics also found the ethanol levels had been so high they’d destroyed the fuel pump. The $1,200 repair bill was covered by Moritz as “good will” because the factory warranty did not apply (using fuel with excessive amounts of ethanol voids the warranty on any components damaged by using such fuel). However, other owners either may not be or may not have been as fortunate as Ms. Jordan. Most victims of such problems may not even be aware of the true cause simply because the fuel they’ve been using hasn’t been tested for levels of ethanol content. At the time of Ms. Jordan’s problem, a Moritz spokesman said the dealership had seen at least 10 other cases of “ethanol poisoning” over the previous six months.

Why is ethanol added to gasoline?

Years ago, tetraethyl lead was added to gasoline as an inexpensive way of boosting octane ratings (an explanation of what “octane” is and how octane ratings are determined is beyond the scope of this article – suffice to say higher octane ratings equate to a fuel being less prone to detonation or pre-ignition in the cylinder of an engine). This is no longer done because it was discovered that the lead was expelled as part of a car’s exhaust gasses, and was getting into the food chain, people’s lungs, and in general creating an extreme health hazard.

As leaded gas was phased out, refiners came up with other ways of enhancing octane ratings. About the same time as this was going on, the Environmental Protection Agency began looking for ways to reduce automotive exhaust gasses that contributed to smog in urban areas. These gasses are primarily carbon monoxide and various oxides of nitrogen.

Side note here – I’m old enough to have driven from Phoenix to Los Angeles by way of what is now I-10 through Indio, Palm Springs, and Riverside, California (in the late 1960s). At the Chiriaco Summit east of Indio, the road was about 1600 feet above sea level and the air was clear. In the distance I could easily see the peaks of the San Bernardino Mountains. Spread out in front of me as I looked toward Los Angeles was an apparent brown ocean – smog. About halfway down from Chiriaco Summit to Indio, I was enveloped in the stuff – I could smell it, I could taste it, and I couldn’t think of a single reason in the world why anyone would willingly live in that kind of atmosphere. That has changed significantly in the years since – in 2005 I made the same drive and the visible air pollution was only a light, whitish-colored haze. I have no doubt that increased pollution controls and regulations have made a massive difference in the amount and nastiness of urban air pollution.

Ethanol, when blended with gasoline, helps reduce exhaust-gas pollution by reducing the amount of carbon monoxide and oxides of nitrogen that are emitted from automobile exhaust pipes. This, I think most people will agree, is a good thing. At the same time, critics claim the reduction of automotive pollution is offset, perhaps more than offset, by the amount of pollution generated during the production and transportation of ethanol. In addition, the argument is made that using ethanol in gasoline merely moves the pollution from urban areas to other areas of the country. Determining an accurate answer to the question of ethanol’s total pollution impact is so complex that nobody has yet come up with a truly definitive answer, primarily because there are so many factors to consider. One reputable study, done by National Geographic Magazine in 2007, found that one unit of fossil fuel yielded 1.3 units of ethanol, for a net energy gain. However, because it takes 1.5 gallons of ethanol to yield the energy equivalent of 1.0 gallons of gasoline, it is possible there’s a net energy loss.

Ethanol is what’s known as an “oxygenating” agent when burned with gasoline. That is, the byproducts of ethanol combustion consist of carbon dioxide and water, and by adding ethanol to gasoline, the chemistry involved during the combustion process yields exhaust gasses with measurably lower levels of carbon monoxide and nitrogen oxides. In addition, it raises the octane rating of gasoline, helping compensate for the absence of tetraethyl lead. California, for some years, used methyl tertiary butyl ether (MTBE) as the oxygenating and octane-boosting agent added to gasoline, but that practice has been discontinued because persistent levels of MTBE, which renders water non-potable, were found in ground water.

What are the problems with ethanol?

1) Ethanol has less stored energy than gasoline. Ethanol contains approximately 76,000 BTU (British Thermal Units) of energy per gallon, while gasoline contains approximately 114,000 BTU of energy per gallon. Put another way, one gallon of gasoline contains about 1.5 times as much stored energy as one gallon of ethanol. Therefore, when ethanol is blended into gasoline, the resulting fuel contains less energy than pure gasoline, and all other factors remaining equal, fuel economy will decrease when ethanol-blended fuel is used. The impact may be relatively small, and may not be noticeable to some drivers. However, assuming no change in driving habits, changing from pure gasoline to E-10 fuel (assuming a true 10% ethanol blend) will reduce miles-per-gallon by approximately three percent. So, if you average 25 mpg in your MINI on pure gasoline, using E-10 is likely to reduce that level of economy to about 24 mpg. Is this a fair price to pay for cleaner urban air? Opinions vary, and keep in mind that if what you think is E-10 fuel really has 15% ethanol by volume, your mpg will drop by about five percent.

2) Ethanol is corrosive. Even fresh from the production plant, ethanol contains soluble contaminants such as halide and chloride ions. (Ions are atoms or molecules where the number of electrons does not equal the number of protons, thereby giving the atom or molecule a net positive or negative electrical charge.) Halide ions chemically attack the oxide films on metals and cause pitting of the metal. This can be a problem in metal fuel lines, for instance, as the halide ions slowly eat through the line. In early 2009 Lexus ordered the recall of 2006 through 2008 models (GS, IS, and LS series) because, according to Lexus, “ethanol fuels will corrode the internal surface of the fuel rails”. On a fuel-injected engine (such as all MINIs have) the fuel is delivered under moderate to significant pressure by the fuel rail, which has one port for each cylinder’s injector. Having ethanol-blended fuels eat tiny pinholes in those rails means that when they fail, they’re going to spray fuel all over a hot engine – a good recipe for an engine fire. (NOTE – This is NOT the cause of the engine fires that led to the recent MINI recall of turbo-charged models.) In addition, long-term use of ethanol-blended fuel may slowly corrode the injectors on a fuel-injected engine, causing the injectors to pulse more fuel than called for, causing the car to run rich (and reducing fuel economy while increasing pollution emissions), perhaps causing excessive carbon buildup on the pistons and valves, and perhaps poisoning the catalytic converter. Most, if not all, automobile manufacturers will tell you their cars are safe to drive using E-10 fuels, but many will also have a statement buried somewhere in their warranty that states the warranty does not cover damage done to a car when fuels containing more than 10% ethanol are used.

Ethanol also has different solvency behavior than gasoline. It will more readily loosen rust and other debris that would otherwise remain undisturbed in a pure gasoline fuel system. This can plug fuel filters, lines, and injectors. It also more readily attacks and removes plasticizers and resins from some plastic and rubber-based materials that are not affected at all by pure gasoline. And finally, liquid gasoline is not a good conductor of electricity (though a spark will ignite the vapors). Ethanol, however, is a very good electrical conductor, and as a result it promotes galvanic corrosion of metallic parts.

3) Ethanol is hygroscopic. That means ethanol loves water – in fact, likes it so much it will absorb water. That’s what people who used to use “dry gas” during the winter were counting on when they added a small amount of dry gas to each fill up. (NOTE: Adding a full 12-ounce container of dry gas to your MINI tank after filling it with 11 gallons of pure gasoline creates a mix that still consists of more than 99% gasoline – to get a fuel mix in your tank comparable to E-10 would require you to add 12 12-ounce containers of dry gas to your tank every time you filled the tank). Dry gas isn’t seen much anymore because most gasoline sold in this country today is blended with ethanol, and there’s no point in adding a small additional amount of ethanol (or isopropyl alcohol, as some dry gas products did) to a tank of E-10 because it won’t significantly increase the amount of water that is absorbed from the fuel. During the winter, condensation in the fuel tank is a somewhat larger problem than during the summer, which is why dry gas was added to a tank of fuel generally only during winter months.

Today the problem is different. With 10% or even more ethanol in the tank, there’s the ability to absorb more moisture from the atmosphere (or from fuel that’s been contaminated by some water). There is a limit, however, to the amount of water that can be absorbed before what’s called “phase separation” takes place. When there is 10% ethanol in the fuel, that limit is at a ratio of 3 gallons of water per 1000 gallons of fuel (in a MINI tank, that’s about five ounces of water per full tank of fuel).

Phase separation can cause very serious problems. When the amount of water absorbed by ethanol in fuel reaches saturation (about five ounces in your MINI tank), the three-component mix of water/gasoline/ethanol is likely to “phase separate” into two distinct levels of liquids in the tank. On the bottom will be the ethanol and water mixed together, and on top will float the lighter gasoline. The gasoline constituting the upper level will now have a reduced octane rating (perhaps as much as three points lower). If the fuel intake sucks just the now-separated gasoline, it is unlikely significant damage will occur at once. The MINI’s engine management computer can largely mitigate this problem by retarding timing to control detonation (also known as “knocking”) but there will be a noticeable drop in performance and fuel economy as a result. However, if the fuel intake sucks the ethanol/water mix, significant engine problems are extremely likely to result within a very short period of time because the MINI engine is not designed to run on fuel with more than 10% ethanol by volume.

4) Other problems: Possibly unforeseen and unintended consequences of widespread ethanol use include:

  • increased food prices world-wide as millions of bushels of corn in this country (as well as others, such as Brazil) are converted to ethanol instead of being exported, used as feed stock for cattle and hogs, or for the manufacture of domestic food products (corn flakes, corn syrup, etc).
  • increased use of marginally productive land for corn, perhaps increasing the amount of fertilizer and soil runoff that gets into the Mississippi River and extends the “dead zone” in the Gulf of Mexico.
  • increased deforestation in Brazil as that country strives to increase ethanol production to meet growing demand for fuels.

Because there are complex political and social issues related to these unintended consequences of ethanol production, I will not comment further.

What do I take from all of the above?

My personal opinion on ethanol-blended fuels is that I won’t use them in my MINI unless I have absolutely no choice. I don’t believe an occasional tank here or there will lead to long-term problems, but I do believe consistent use of ethanol-blended fuel is a recipe for expensive out-of-warranty repairs to the fuel pump, the fuel lines, the fuel injectors, and perhaps the engine itself. If I were like some owners and leased my MINI, or like some other owners who get a new car shortly after the new-car or extended warranty expires, perhaps I wouldn’t worry about this and I’d just let someone else inherit the problems. However, I already have 100,000 miles on my MINI, and my intent is to keep the car for many more years and many tens of thousands more miles. I feel any premium I pay for pure gasoline the vast majority of the time is a small price to pay to be reasonably sure I don’t end up with very expensive problems caused by using ethanol-blended fuel on a consistent basis.

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