Although ethanol alcohol is mostly made from corn, it seems to be a real hot potato! Almost all pump gasoline today contains 10 percent ethanol (E10) because the Renewable Fuels Standard Act requires it. The reasons why are partially practical, partially political and partially economic.
The use of ethanol as an alternative motor fuel goes way back, but gained momentum in the 1970s following the OPEC oil embargo of 1973 that created fuel shortages and soaring gasoline prices in the U.S. A blend of 10 percent ethanol alcohol and gasoline called “gasohol” was introduced in Iowa as a means of extending fuel supplies. Gasohol soon became available in several other mid-western states because it could be easily made from locally grown corn.
In those early days, producing ethanol was a small-scale business that didn’t have a big impact on fuel supplies, corn prices or politics. But as time went on, ethanol production grew and started to become a major player in the alternative fuels market. Farmers liked it because it created a new market for all the surplus corn that kept piling up year after year. Politicians liked it because it allowed us to use homegrown biofuel to offset oil imports from the volatile Middle East. And the automakers liked it because ethanol allowed them to meet government-mandated Corporate Average Fuel Economy (CAFE) standards by offering “Flex Fuel” vehicles that can burn E85 (85 percent ethanol and 15 percent gasoline).
Last year, more than 13 billion gallons of ethanol were produced in the U.S. to meet fuel demands. That’s 13 billion fewer gallons of gasoline that had to come from conventional petroleum sources. Ethanol production has become big business today and is now one of the cornerstones of the agricultural economy in most corn-producing states. The top corn producing states are Iowa, Nebraska, Illinois, Minnesota, South Dakota, North Dakota, Indiana, Wisconsin, Ohio and Kansas. Fuel grade ethanol is currently being produced in more than 180 plants scattered across 27 states.
The Environmental Protection Agency (EPA) has approved the use of E15 (15% ethanol blend) gasoline for general use in 2001 and newer vehicles, which is just now starting to appear at gas stations in various states. There is talk of offering a special E30 (30 percent ethanol blend) high octane premium fuel for use in next generation engines that will be optimized for 95 octane fuel. These will be small displacement four cylinder turbocharged engines that are designed to offer improved fuel economy with V6 or V8 performance.
Next Gen Flex Fuel
The automakers are also considering next generation engines for Flex Fuel vehicles that will be optimized to burn E85. These engines will have much higher static compression ratios (up to 14 to 1) compared to today’s Flex Fuel vehicles, which are NOT optimized for E85 because they also have to burn regular 87 octane gasoline. Optimizing engine design for E85 means taking advantage of E85’s much higher octane rating, which can range from 99 to 105 depending on the season and blend.
Although E85 pump gas can contain up to 85% ethanol, it may actually contain as little as 70% ethanol during cold winter months to improve fuel volatility and cold starting in some areas of the country. Gasoline refiners can also play around with the mix to optimize profits depending on the relative costs of gasoline and alcohol. Using a higher percentage of alcohol in E85 allows the use of lower octane (cheaper to produce) gasoline.
If automakers start optimizing next generation Flex Fuel engines for E85, they can increase compression ratios and crank up the boost pressure to squeeze even more performance and fuel economy out of small displacement engines.
So how does all of this affect engine builders? For one thing, it means you’ll probably be seeing more engines with significantly higher compression ratios in late model vehicles. You will also be seeing more small displacement turbocharged engines that are optimized for higher octane ethanol fuels. The growing acceptance of ethanol as a high performance motor fuel also means it is being used at more racing venues as an alternative for expensive racing gasoline or methanol.
Differences In Alcohols
A lot of people don’t know the difference between ethanol and methanol. Both are alcohols, but each has its own unique properties. Ethanol is mostly made from corn in the U.S. by fermenting corn starch and distilling the liquid using essentially the same process that moonshiners and alcohol distillers use to make liquor. However, ethanol can also be made from sugar cane (as they do in Brazil where sugar cane is their main crop) or even cellulose (things like corn stalks, leaves, switch grass, wood scraps or even scrap paper). You can drink pure ethanol because it is essentially nontoxic in reasonable quantities, but methanol will kill you if you drink it because it is highly poisonous.
Methanol is mostly made by processing methane (natural gas) and combining hydrogen with carbon monoxide and carbon dioxide. For a period of time, methanol was used to make MTBE which was added to gasoline as an octane booster. MTBE replaced tetraethyl lead as a fuel additive because lead fouled catalytic converters and oxygen sensors. However, the use of MTBE as an octane boosting fuel additive in the U.S. was discontinued when concerns arose over its toxicity and environmental impact. This is one of the reasons why ethanol is now used with gasoline as an octane booster instead of MTBE.
As a racing fuel, methanol is great stuff. So is ethanol because both fuels have extremely high octane ratings. Methanol has a RON octane rating of 123, while straight ethanol has an octane rating of 130 (RON), 102 (MON) and a pump rating of 116. Ethanol racing fuels, which are typically available as either E85, E90 (90% ethanol) or E98 (98% ethanol) carry octane ratings up to 116 depending on the other ingredients in the fuel.
One of the drawbacks of alcohol fuels is that they contain less energy (hydrogen/carbon bonds) than gasoline. This means alcohol fuels require a much richer air/fuel mixture to deliver the same amount of power. Regular 87 octane pump gas typically contains around 125,000 BTUs (British Thermal Units) per gallon compared to 64,600 for methanol or 84,600 for methanol. Consequently, an engine running methanol requires roughly twice as much fuel for the same bang as an engine that’s burning gasoline. With ethanol, the numbers are a little better, with the engine needing about 30 percent more fuel for the same bang. However, if an engine is optimized to take full advantage of the higher octane ratings of either methanol or ethanol with more compression and spark advance, the same naturally aspirated engine will typically produce 2 to 5 percent more power on alcohol than gasoline. If we’re talking a turbocharged or supercharged engine, the power gains can be even greater because the higher octane allows increased boost pressure.
As for methanol or alcohol versus racing gas, the advantages are not as great because racing gas can also be formulated to have high octane ratings too. But racing gas is expensive, much more expensive than, say, E85, which typically sells for 15 to 28 percent less than regular pump gas at most retail outlets. Current prices for E85 in the Midwest range from $1.32 to $1.69 per gallon.
Racing E85, which is more expensive than E85 pump gas, is still cheaper than most other racing fuels or methanol. Racing E85 is formulated to a higher quality standard and consistency to reduce tuning variables. Various blends can deliver octane ratings of 108 to 116. E85 is also being marketed as a “green” alternative to racing gas and methanol. It’s nontoxic (except for the gasoline portion), burns clean, produces fewer pollutants than fuels with long chain hydrocarbons, and is made in the USA from homegrown renewable resources (corn).
Back in 2012, NASCAR made the switch to E15 to improve its environmental image. There is talk that NASCAR may eventually switch to E85 at some point down the road. Many other racing venues including Indy cars, circle track cars, drag cars, road racing cars and even go-carts have switched to ethanol blends – if for no other reason than to keep racers’ and fans’ eyes from watering or their noses burning from methanol exhaust fumes. Ethanol does improve the air quality on the track, in the pits and even in the stands.
Most of the myths and negative comments you have read about ethanol are false and typically originate with Big Oil interests or people who have not studied the facts. Most of the good stuff you read about ethanol comes from corn growers, ethanol producers and racers who have switched to ethanol.
Common myths are that ethanol takes more energy to produce than it delivers, and that making fuel out of food drives up food prices for the poor. Both are false. Ethanol produced from corn or sugar cane is energy positive and yields more energy than it takes to plant and produce it. The U.S. Department of Agriculture says ethanol yields 2.3 BTUs for every BTU that is used to produce it – which is actually more efficient than gasoline. Making gasoline out of petroleum requires drilling, transporting it half way around the world and energy-intensive refining. And this does not include the military, economic, social and political costs of getting involved in endless wars over oil (Gulf Wars I and II).
As for driving up the price of tacos in Mexico, the type of corn that is used to produce ethanol is yellow field corn. This variety of corn is used for animal food (corn fed beef), to produce fructose (corn syrup sugar that is used as a sweetener in soda and many other processed foods) or to make ethanol. In fact, one of the byproducts of ethanol production is the leftover mash, which is also fed to animals. One bushel of corn yields 2.8 gallons of ethanol plus 17 pounds of livestock feed. The price of corn is currently around $3.78 a bushel, which is half the price of what it was in 2013. So if the price of tacos in Mexico has gone up you can’t blame ethanol production for the price hike. Blame a strong U.S. dollar, transportation and distribution costs.
Here’s another myth: adding ethanol to gasoline drives up the price of gasoline. Not true. According to USDA studies, it actually drives down the price of gasoline an average of 25 cents a gallon. Yes, corn growers and ethanol producers receive government tax breaks and credits, but it’s peanuts compared to the billions in tax breaks and write-offs Big Oil has enjoyed for decades.
Ethanol does not vaporize as easily as gasoline at low temperatures, which is why E85 contains 15% gasoline for easier cold weather starting. But since most racing venues are run during warm weather, cold starting is not a concern.
Ethanol won’t ruin an engine. Its high octane rating resists detonation – provided the fuel mixture is correct. Ethanol requires an air/fuel ratio of about 9 to 1, which means an engine that’s being converted to ethanol will usually require a higher capacity fuel pump, fuel lines and higher flow fuel injectors or larger carburetor jets. It’s the same story with methanol, except that methanol requires an even richer fuel mixture of around 7 to 1.
Ethanol and methanol can be corrosive to uncoated aluminum and zinc, which means carburetor and other fuel system components should have a protective coating to prevent corrosion. Most aftermarket carburetor suppliers have carburetors designed for alcohol fuel applications with protective anti-corrosion coatings and oversized fuel metering circuits and main jets to handle the richer fuel mixtures. The floats in alcohol carburetors are also brass or alcohol-resistant plastic.
E10 will NOT damage fuel system components in current production vehicles or most older vehicles, and E15 will usually cause no problems either in older vehicles even though it is only recommended for use in 2001 and newer vehicles.
Most vehicles built since the mid-1990s cars have fuel system components that are alcohol-resistant. Flex Fuel vehicles are the most rugged and are designed for either gasoline or E85. What happens if somebody accidentally fills up an older vehicle with E85? The engine will run lean if it has a mechanical carburetor, but most fuel injection systems will be able to compensate for the alcohol. Running E85 in a vehicle that is not Flex Fuel certified is not recommended, but one tank won’t damage the fuel system on most older vehicles. However, prolonged use of E85 in an older vehicle that was not designed to tolerate any alcohol may cause some rubbers or plastics to swell. The alcohol may also corrode an unprotected carburetor or cause a plastic carburetor float to absorb fuel.
Concerns about ethanol loosening fuel varnish and gumming up the fuel system are also unfounded. What do you think the main ingredient is in many fuel system cleaners? It’s alcohol. It’s a great solvent. If an ethanol blend is used in a high mileage vehicle that has NEVER seen any alcohol, it might plug up the fuel filter if the tank and lines are coated with fuel varnish – but that’s unlikely because “pure” gasoline is extremely hard to find anywhere in the U.S. and has been unavailable for many years.
Will ethanol foul the oil and wipe out the bearings? If an engine has a LOT of blowby and is being overfueled with an unusually rich alcohol fuel mixture (think Top Fuel dragster or Alcohol funny car), alcohol can contaminate and dilute the oil – but so can racing gas or pump gas under the same circumstances. Contaminated motor oil may appear milky, which means it should be changed. Most racers keep a close eye on their oil anyway and will change it before any lasting damage occurs.
For street or street/strip applications that burn E10, E15 or E85, any off-the-shelf motor oil that meets current American Petroleum Institute (API) “SN” or ILSAC GF-5 specifications contains additives that keep alcohol vapors in the crankcase emulsified so the alcohol and oil don’t separate.
Racing oils, however, are different. Many racing oils to not meet API SN or ILSAC GF-5 standards because they are formulated with different additives (more anti-wear ingredients such as ZDDP and less detergent). Consequently, some race oils should NOT be used with alcohol fuels, especially if the oil is not changed regularly. Many aftermarket racing oil suppliers do have special performance oils that are designed for alcohol fuel applications, so follow their advice as to which oils are recommended for alcohol fuels and which oils are not.
Engine Building Tips
If you are building an engine for a customer who wants to run some type of alcohol fuel in his engine, there are several steps you can take to optimize engine performance and longevity:
• Increase the static compression ratio to take full advantage of alcohol’s higher octane rating. A compression ratio of up to 14.5 to 1 works well with E85, E98 or methanol in most engines.
• Crank up the boost pressure on turbocharged or supercharged engines to take maximum advantage of alcohol’s higher octane rating.
• Add several degrees of additional timing advance to the spark curve. Alcohol burns a little slower than gasoline so it needs more time to fully burn.
• Alcohol burns somewhat cooler than gasoline. This often results in a lower engine operating temperature (15 to 20 degrees cooler). This reduces the risk of overheating, which means you can also run a slightly smaller radiator and/or less grill opening to improve aerodynamics and reduce drag on a circle track car.
• Install coated main and rod bearings to provide additional insurance against any lubrication-related issues that may arise if the oil is contaminated with excessive amounts of alcohol. Coating bearings will also provide additional protection against dry starts and bearing damage if the engine loses oil pressure during a race.
• Install pistons with an anti-scuff coating on the skirt for added protection against any lubrication-related problems in the cylinder bores.