EPA Admits Ethanol Damages Engines

04/22/2014 @ 10:31 am, by Bryan Delohery13 COMMENTS


Since Congress passed the Energy Policy Act of 2005 as a means to “combat our growing energy problems” and “reduce our independence on oil”, the debate over how safe ethanol additives really are has raged on.

As you may know, the Act lead the introduction of E10 (gasoline with 10% ethanol), which vehicle owners have been claiming causes serious damage to engines, such as damaged catalytic converters, improper combustion, and component deterioration.

While proponents of ethanol claim that it is a cleaner burning, higher octane fuel source that is renewable, opponents feel that the mixture of gasoline and ethanol is causing more problems than it is solving. This week marks a victory for the latter camp, as the EPA has now publicly confirmed that ethanol does cause serious damage the engines.

The announcement comes in the form of a new rule proposal set forth by the Federal Trade Commission which would require a label on gas pumps supplying high ethanol content blends such as E15.

According to the EPA, ethanol impacts motor vehicles in two primary ways. First … ethanol leans the [air/fuel] ratio (increases the proportion of oxygen relative to hydrocarbons) which can lead to increased exhaust gas temperatures and potentially increase incremental deterioration of emission control hardware and performance over time, possibly causing catalyst failure.

Second, ethanol can cause materials compatibility issues, which may lead to other component failures. What material compatibility issues would they be referring to? Ethanol has been known to  wreak havoc on fuel systems, deteriorating plastic and silicone components such as hoses, fuel pumps and filters, gas tanks, and fuel injectors.

Among its other talents, ethanol also has the ability to etch aluminum and magnesium, as well as absorb moisture from the air, allowing a water/alcohol mixture in the fuel tank.

The American Motorcycle Association has been actively fighting the distribution of E15 and applauds the EPA’s decision to reassess the further distribution of E15.

AMA Vice President for Government Relations, Wayne Allard said “now the EPA acknowledges that ethanol itself is harmful to emissions hardware and other components on all motor vehicles. It is time for the federal government to pause, take a hard look at this product and change its entire approach to ethanol in fuels.”

While this is a step in the right direction to curb the use of E15, there are still many vehicles, both on and off-road, using E10 which, while not as dangerous, is still causing problems.

Any updates or changes made to EPA legislation can be found on their Renewable Fuels Regulations and Standards webpage.

Source: AMA

  • JoeD

    Less publicized is the real reason ethanol was adopted. The vote on a crucial piece of legislation was needed. Senator Harkin, from a corn state, would vote in favor if the corn/ethanol cartel was implemented. Surely others were involved as well but Harkin’s name floated to the top in news reports.

    Another side effect is reduced fuel mileage from E10. Less power from the same amount as gasoline means more overall fuel usage to achieve the same results.

    The Government always has our best interests at heart, right?

  • Here in Brazil, the gas has 25% ethanol.

    I have a 250, single cylinder Yamaha…. 55.000 kilometers, only changing transmission, tires and oil. Here, the richer people has Hornets, BMWs and others Sport/Dual Sport “big” bikes. BMWs and Suzukis here can surpass 100.000 kilometers easily.

    I just really don’t understand.

  • jr2


    Short answer, it’s not that US engines can’t last… it’s that the pollution control systems are more easily effected by higher ethanol levels, and these systems are tied to overall engine capabilities and lifespans.

    Details (as I understand them)

    The US has “evaporative emission controls”, where gasoline that evaporates is not allowed to “vent” to the atmosphere, and is trapped and recirculated into the fuel tank. This system is filled with hoses, and other components that are susceptible to deterioration due to higher levels of ethanol in the fuel. These evaporate collection systems have been on US autos for a long time, and are found on more modern motorcycles. Could these systems be designed to be resistant to the higher levels of ethanol in fuel, of course they could be, but they currently are not.

    As best as I can tell… Brazil doesn’t require evaporate systems for motorcycles (yet)


    Additionally, the catalytic converters in US automobiles are designed to run in a reasonably small (but high) temperature range (to be maximally effective). Ethanol can (repeat, can) cause these converters to run hotter than the optimum temperature, where the catalytic materials can begin to degrade. Typically (a little help here US folks) in the US, if a catalytic converter is rendered inoperative the owner of the vehicle is not required to replace it due to it high costs. So, if the converter is degraded by ethanol levels then emission levels increase, defeating the reason to have the systems in the first place.

  • Kevin White

    Please let’s get a change on E10 too.

    I’m a little confused on this new news though. I had read that E15 pumps would be marked E15 and would be in addition to E10 pumps all along. Were they trying to mandate E15 for all pumps across the land as of late?

  • Kevin White

    I wish not replacing the cat had been an option back in 1996 when my 86 RX-7 destroyed its cat.

  • Not to mention the Alcohol damaging plastic gas tanks such as in my Monster and Aprilia Rsv. Both are on gas tank #2 !! Thanks EPA really appreciate it.

  • paulus

    It’s a ‘growing’ pain.
    The oil is finite… this is for sure.
    We are the early adopters of alternative fuels. There will be hardships and learning curves as the transition is made to different fuels, lessons learned from incompatible materials etc, but it is inevitable that combustion engines must eventually run on something other than fossil fuels.
    My KTM runs great on ethanol mix, my Kawasaki doesn’t…. hopefully in future all motorcycles will be developed to run on the fuels of that time.

  • buellracerx

    @jr2 – agreed, increased ethanol content requires a paradigm shift with regard to plastics in the fuel system – fine for current and future models; less than ideal for older bikes in circulation. Manufacturers need to make a conscious effort towards changing materials and adding coatings…it does add cost, so expect certain ones to hold out as long as possible.

    While running leaner may lead to higher end gas temps, wouldn’t this be balanced by ethanol’s higher volatility, higher heat of vaporization, and lower specific energy content with respect to gasoline blends? Also, end gas temperature does go down after a certain point as you go more lean…guessing on-road (and certainly off-road) mc emissions requirements simply aren’t stringent enough to require this level of lean running yet. The EPA’s vague statement is surely driven by the wide range of methodologies in hardware and fuel mapping.

    Let’s understand the effects completely before simply condemning ethanol as a fuel…it does have some nice advantages.

  • @Kevin White, the 2007 Energy Independence and Security Act states a target goal of 36 billion gallons of biofuel must be created by 2022, which means that to be in accordance with the law, auto manufacturers will be producing vehicles that are engineered to run on E40. Over the course of the next eight years you will begin to see E15, as well as E40 and E85 at more gas pumps nationwide. E10 may end up sharing the same fate as non-ethanol gasoline, which is unobtanium.

  • L2C

    Just say no to high fructose. And yes to sucrose.

  • Neil

    Jr2- Here in North Carolina, the ethanol is creating a bit of a problem with the states vehicle emissions requirements. In order for a vehicle to be able to renew its registration every year, it must first pass a safety and (if 1996 or later) an emissions inspection. The number of vehicles I see that are unable to renew their registrations are because of emissions related problems. This winds up costing people hundreds of dollars to replace sensors, cats, and related parts. The vehicle would be otherwise safe to operate if it wasn’t for the check engine light on. Here at the coast, we do have the availability of Non-ethanol fuels so for the older cars and motors there is an option. Even more crazy….it just makes no sense that we would burn our food supply with all the populations on this planet needing it for consumption…. Politics….

  • a tom

    Of course, this is all still ignoring the fact that the USA utilises CORN when making ethanol, whereas Brazil uses SUGARCANE, and utilising corn as the source of ethanol has been shown to be less efficient than that of sugarcane.

    Granted, the USA, or more specifically corn-growing states, may not have the environment for large-scale sugarcane growth, but there is a suggested alternative in sugar beets.

    (To be frank, the actual environmental benefit of bio-fuel from crops is also questioned, though that’s a separate argument and brings with it points of foreign dependency.)

    Politics are unfortunately at the very heart of the push on corn-based ethanol-enhanced fuel, and the EPA, or at least senior management / govt stakeholders, are more than happy to continue to pander to the corn industry.

    Try to address that, then figure out if the continued use of ethanol for vehicles is viable.

    Of course, can’t put it past them to just go in and screw the consumer by forcing higher manufacturing costs as suggested above, protecting the corn industry’s interests…

    And on fuel in 2022, here’s to electric vehicles actually catching on, which would shift the politics to being the electricity generating companies vs the corn industry, a much more even fight… (Though still leaving ICE drivers to their fates…)

  • meatspin

    http://pure-gas.org/ is what I use. They also have an app for it. If you have an older bike you probably know that ethanol free is the way to go. If not, you will.