The Damaging Qualities of E15

Story by Costa Mouzouris//
August 1 2014

Remember when your mother told you to eat your broccoli and you fought tooth and nail not to? She told you it was good for you, but to an eight-year-old, the stuff tasted like crap. Well, E15 is like broccoli to your bike. It’s supposed to be good to the environment, but your bike sure doesn’t like the taste.

While E15 gasoline isn’t available in Canada, at least not yet, you should be aware of it if you travel to the United States, especially by motorcycle, and you should avoid using it. E15 is a gasoline mixture that blends 85 percent gasoline with 15 percent ethanol. Ethanol, or ethyl alcohol, is derived from grain, and in the States, that grain is primarily corn.

A battle is ongoing down south between auto manufacturers and the U.S. government over the use of E15; carmakers will not honour the warranty if ethanol is at the source of the damaged components. American policymakers claim there’s no danger in using E15 as long as your car was manufactured after 2001.

Ethanol does not contain as much combustible energy as gasoline, so the more of it that is in the gas, the less efficient the engine will run. This is why many drivers who use ethanol-blended fuels also report a drop in fuel mileage. However, since ethanol burns cleaner, fewer dangerous emissions are spewed out the tailpipe, which is one of the principal reasons E15 was developed. It also puts farmers to work because of the increased demand for corn.
However, environmentalists dispute the claim that E15 is greener than regular fuel, because to increase their yield of corn, farmers have been cultivating unproductive land previously unsuitable for farming, which leads to increasingly dirty runoff. Environmentalists are also in a hoot because the production of E15 consumes what could otherwise be used as a food source, whether it be for human consumption or feed for livestock, and this could potentially drive up the cost of food.

Political tug-of-war aside, the bottom line is that E15 is not good for your bike, and it’s not good for your gas-powered lawn equipment, either. A high ethanol content in gasoline has been proven to cause damage to fuel systems, especially in cars built before 2001 and all motorcycles, and has reportedly been associated with engine damage in some cases. It dries out and hardens rubber fuel line and gaskets, and can potentially cause damage inside the engine, particularly to the parts associated with the combustion chamber, like the pistons, cylinder and valves. It also leans out the mixture and runs hotter, both of which can be damaging.

Motorcycle makers have not been as vocal as automakers about the use of E15, but motorcycles were never designed to use that much ethanol. Most owner’s manuals contain a disclaimer warning you to avoid using gasoline that contains more than 10 percent ethanol, which is very common in the U.S. and in Canada – and this is the rule you should adopt when filling up. In fact, for the best results, try to use gasoline that has no ethanol content, if you can still find it.

Selecting a high-octane fuel is no guarantee that there won’t be ethanol in it. Petro Canada currently offers the highest pump octane with its Ultra 94 gasoline, and according to its website, “Ultra 94 contains ethanol. Due to the fact that various fuel grades are blended at the point of sale, most grades of Petro-Canada fuel may now contain up to 10 percent ethanol. This represents a change from the previous state, where premium fuel was ethanol-free at Petro-Canada.” Shell claims its V-Power premium gasoline does not contain ethanol in Canada.

In April of this year, the AMA (American Motorcyclist Association) issued a press release that the EPA had finally acknowledged that E15 can be harmful to engines due to increased exhaust temperatures. A month later, the AMA followed up with another release, this time stating that a group of U.S. congressmen agreed that the Renewable Fuel Standard, the basis of the E15 debate, is flawed.

The RFS program, created in 2005, required that 7.5 billion gallons of renewable fuel, primarily ethanol, be blended into gasoline by 2012. The program was revised in 2007, and the amount of renewable fuel to be blended into gasoline was reset to maximum of 36 billion gallons by 2022. This was before the latest finding on E15 and its potential to damage engines.

“The federal government’s RFS is a failed strategy that must be reconsidered,” said the AMA’s Wayne Allard in the most recent AMA release. What anti-E15 lobbyists are demanding is simply a reduction of the amount of ethanol used in fuel to 10 percent or less.

Fortunately, most gas pumps in North America are now labelled, showing the maximum amount of ethanol that may be blended in the fuel; gas pumps dispensing E15 will be labelled as such. Unfortunately, you can never know exactly the percentage of ethanol in the fuel you pump into your bike, because it varies – though again, if the pump indicates that the fuel may contain up to 10 percent ethanol, it will not exceed that amount.

You can find a list of gas stations that offer ethanol-free gasoline in North America at

Technical articles are written purely as reference only and your motorcycle may require different procedures. You should be mechanically inclined to carry out your own maintenance and we recommend you contact your mechanic prior to performing any type of work on your bike.


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