When you think alternative fuels, natural gas, biodiesel or hydrogen immediately come to mind. Often missed is another biofuel—ethanol. Indeed, many Americans are already driving an alternative fueled vehicle and may not realize it. Since the late 1990s, Ford, GM, DaimlerChrysler and other automakers have sold millions of Flexible Fuel Vehicles (FFV). These FFVs can operate on E85, unleaded gasoline or any combination of the two. E85 is a blend of 85% ethanol (ethyl alcohol) and 15% unleaded gasoline.
In the United States, ethanol is usually produced from corn, but other grains like wheat or barley can be used. In Brazil, 40% of the ethanol fuel used by its cars and trucks is produced from sugar cane. Unlike gasoline, ethanol can be produced from domestic feedstocks, not imported petroleum.
Besides being a renewable biofuel, burning ethanol results in modest reductions of harmful hydrocarbon and benzene emissions as well as reduced carbon dioxide. While the benefits of using E85 might be small on a per-vehicle basis, if used in millions of vehicles the results could be a rather dramatic help in reducing the nation’s dependence on imported oil.
Ethanol should not be confused with gasohol, which is only 10% ethanol and 90% gasoline. Gasohol, or E10, is not considered an alternative fuel. Instead, pure ethanol is blended with small amounts of gasoline to improve engine starting and for safety reasons. Pure ethyl alcohol burns with a colorless flame, and thus, could be a safety hazard.
Modifying an engine to operate on E85 is pretty simple—add a fuel sensor to detect the ratio of ethanol to gasoline, replace fuel system components that are not compatible with the more corrosive ethanol and reprogram the engine management computer. While these modifications are simple, they are also required to burn E85. Unlike gasohol, ethanol should not be used in vehicles other than FFVs.
Drivers will not probably notice any difference between operating on E85 versus gasoline. While ethanol produces less energy than gasoline, it has a higher octane rating. Typically, there is a 5 to 15% decrease in fuel economy depending on operating conditions. Currently, E85 is more expensive because of the added cost to blend ethanol with gasoline as well as the added cost to ship E85 into areas where corn is not grown.
The E85-version of the Chevy Police Tahoe is the only OEM alternative fuel police vehicle available in the United States. The specs show no significant difference in horsepower or torque between the E85 version and the gasoline-only version. In fact, the E85 Tahoe is slightly faster than the gasoline version. However, the E85 vehicle gets about 4 to 5 mpg less than the gasoline version, highlighting the reduced energy content of ethanol. The EPA City for the E85 is 11 mpg compared to 15 mpg for the gasoline version.
The poorer fuel economy and now higher cost of E85 fuel means running on this alternative fuel may be a more expensive proposition. Couple this with the current limited availability of E85 and there may be little reason today to use E85, unless a fleet has a mandate to use alternative fuels. But this could change.
For example, if the price of gasoline climbs to where it significantly exceeds the price of E85, drivers could demand it for their FFVs and traditional fuel suppliers will see a profit in meeting the demand. Indeed, E85 and the millions of FFVs could be considered an emergency energy resource in times of a gasoline shortage.
Few motorists are filling their FFVs tanks with E85 since there are only about 400 refueling stations dispensing it in the United States, though they are growing in number That is because the 1988 Alternative Motor Fuels Act provided incentives to automakers to produce alternative fuel vehicles, but no companion incentive for developing of the required refueling infrastructure.
Also, ethanol cannot be transported readily through existing petroleum pipelines and must now be transported by barge, rail or truck. Thus, petroleum refiners have shown little interest in selling this competitor to gasoline. Because of this disconnect, the intended goal of reducing the nation’s dependence on imported oil, and to reduce C02 emissions, with ethanol has not happened.
E85 has been determined to be a flammable liquid by OSHA, and should be handled accordingly. The safety standards for handling E85 are the same as those for gasoline. The National Fire Protection Association (NFPA) codes 30 and 30-A pertain to refueling stations and the handling of motor fuels and other combustible liquids. Like with any fuel, E85 vapors can travel along the ground or be moved by ventilation and ignited by sources such as pilot lights, sparks, electric motors, static discharge or other ignition sources.
The Alternative Fuel Vehicle Institute offers a downloadable presentation, E85 as a Vehicle Fuel to educate fleet managers about E85. The presentation can be found at http://www.eere.energy.gov/afdc/e85toolkit/pdfs/e85_driver_training.pdf.
William D. Siuru, Jr., PhD, PE is an automotive journalist and can be reached at firstname.lastname@example.org.