For many motorcyclists, the only fuel-related concern besides the price of gas is not accidentally grabbing the green-handled diesel pump. Few of us pay close attention to ethanol content because it’s become so common in our fuel supply (as an oxygenator) since the additive MTBE was banned by most states during the ‘90s. But now the American Motorcyclist Association (AMA) is urging motorcyclists in particular to pay closer attention to ethanol content, citing possible concerns regarding performance, fuel economy, and engine durability. The AMA is even lobbying the U.S. government to persuade the Environmental Protection Agency (EPA) to conduct new tests on the effect of ethanol-blended fuels on motorcycles and ATVs, so consumers can make more educated fuel-buying decisions.
Most modern vehicles can safely run on a blend of up to 10 percent ethanol (E10). Flex-fue
At issue is a 2011 EPA waiver allowing the sale of E15 fuel—a blend of 15 percent ethanol and 85 percent gasoline—that is EPA-approved for 2001-and-newer cars and light trucks but has not been approved or tested for use in motorcycles, ATVs, or other small engines. The AMA worries that motorcyclists who don’t pay attention to E15 labeling might unknowingly cause damage to their engines, and possibly even void their warranties. The AMA supports bills in both the U.S. House and Senate that would overturn the existing EPA waiver and prevent the granting of similar waivers for any blend beyond E10, unless further testing is conducted specifically regarding the use of ethanol fuels in motorcycles.
Ethanol is grain alcohol typically produced from corn in the U.S., where slightly more than 60 percent of all global ethanol production happens. There are numerous advantages cited for adding ethanol to gasoline, besides reducing environmental damage caused by MTBE. Ethanol is a biofuel produced from renewable resources, which can reduce our dependence on fossil fuels and foreign oil, increasing our country’s energy independence (though fossil fuels are of course consumed in ethanol production). Supporters say increased ethanol use could also reduce fuel prices too.
Critics, however, suggest the downsides of ethanol outweigh the benefits. The energy-unit-per-volume of ethanol is about 35 percent lower than gasoline. Because fuel economy is proportional to energy content, increasing the ethanol quotient can reduce fuel mileage. The effect with E10 is usually negligible—about 3 percent—but fuel economy for E85 vehicles is usually about 25 percent less than with gas. Ethanol is more corrosive than gasoline, which can promote engine damage, especially to aluminum. Ethanol is also hygroscopic (it absorbs water vapor from the air), which can be especially problematic for motorcycles that aren’t ridden every day. Then there are a host of political concerns, including the “food-versus-fuel” debate that contends that converting arable land for ethanol production will increase food costs for Americans. In light of these concerns, critics—including the AMA—are demanding more scientific research on the subject of ethanol usage so consumers, including motorcyclists, can make more informed fuel purchasing decisions.
Until these issues can be resolved, it might be a good idea to take a quick glance at the formulation sticker—in addition to the price and the pump handle color—the next time you top off your motorcycle tank.
Is Ethanol the Ultimate Power Fuel?
While ethanol can be problematic for motorcycles that are used infrequently or by less-than-attentive owners, the biofuel’s intrinsic properties can add up to a huge power advantage for high-performance enthusiasts. Ethanol’s higher octane rating allows savvy tuners to run hugely increased compression ratios for much-improved performance. This is just one of the reasons that the Indy Racing League (IRL) uses E100—pure ethanol—to fuel its 230-mph race cars, and NASCAR has used E15 since 2011. Naturally, some motorcycle racers—especially drag racers and land-speed competitors—are increasingly utilizing ethanol-blend fuels with excellent results.
Ethanol contains 37 percent oxygen by weight, giving E100 an effective octane rating of 115. The more-commonly available E85 blend has an effective octane rating around 105—significantly higher than pump gas. The enhanced resistance to detonation and cooling properties delivered by these high-octane fuels allow ethanol engines to be tuned with very high compression ratios and radical ignition timing, and still safely produce superior horsepower compared to a conventional, gas-fueled engine.
There is a downside, of course—ethanol’s lower energy content means that an E100 engine is typically around 30 percent less efficient than its gas counterpart—but during most racing competitions, at least, miles-per-gallon is not a primary concern. Such is the cost of speed.