Safely Testing the EVAP System on a FFV with E85
With more than 10.6 million Flex Fuel Vehicles (FFVs) on the road today, there’s a good chance that one has already been in your shop for service. The difference is the FFV that pulls in today or tomorrow may have E85 as its primary fuel source, rather than gasoline.
As a blend of 85 percent ethanol and 15 percent unleaded gasoline, E85 has significantly different vapor behaviors than conventional gasoline. To minimize potential EVAP leak-testing hazards when using smoke technology, virtually all OEMs require using only STAR Diagnostic Smoke® Technology. OEMs require this for several reasons, one of which is that STAR Technology is designed for use with any inert gas carrier.
Experts, including SAE International, concur and support the safer testing practices of using an inert gas, such as nitrogen, as the carrier gas for the smoke vapor when leak-testing a vehicle’s EVAP system. Scientific research shows that less than 12 percent of oxygen can render a fuel tank filled with E85 flammable and the air we breathe contains approximately 21 percent oxygen. Gasoline vehicles have very similar hazard concerns, but the window for error in a FFV is even narrower.
Flex Fuel Vehicles Fueling E85 Use
In the U.S. market, FFVs are produced by Chrysler, Ford, GM, Isuzu, Mazda, Mercedes-Benz, Nissan, Toyota and Bentley, with more than 70 FFV models available. Flex fuel vehicles are usually priced the same as gasoline-only vehicles.
As consumer demand for alternative fuel vehicles continues to increase, auto manufacturers are working to produce more FFVs. The major automobile manufacturers in the United States, including Ford, Chrysler and General Motors, have pledged to make 50 percent of all new vehicles coming off their assembly line model year 2012 and beyond FFVs.
There are many industry groups that support E85 and a wealth of resources that provide information about E85 and FFVs. The ethanol issues being addressed and debated by the 112th Congress include the Renewable Fuel Standard, greenhouse gas emission regulation, loan guarantees for advanced and cellulosic ethanol technologies, and expanding the use of ethanol beyond current 10 percent limits.
E85 and FFVs also are likely to be addressed at the state level, and many states already offer incentives related to alternative fuels and advanced vehicles for various users, including vehicle owners or drivers, fueling infrastructure owners, alternative fuel purchasers or producers, and alternative fuel vehicle manufacturers.
E85: Growing As A Renewable Fuel
E85 is a renewable and domestically produced fuel and cannot be used in a conventional gasoline-only vehicle. Instead, it is used in a FFV, which can typically use unleaded gasoline or any blend of ethanol up to this 85 percent level.
Flex fuel vehicles have been around for some time, with the first one dating back to a 1908 Model T built by Henry Ford. Vehicle manufacturers started producing greater quantities of FFVs in the 1990s, however, consumers who own them largely have used gas as the primary fuel source. Only recently has there been a growing awareness of FFVs and the benefits of using E85 as the renewable fuel of choice.
The appeal of E85 is that it stands to reduce U.S. dependence on foreign oil and reduce greenhouse gas emissions (GHG) by 35 percent to 46 percent compared to gasoline. According to the U.S. Dept. of Energy’s Argonne National Laboratory, the production and use of 13 billion gallons of ethanol in the United States in 2010 reduced GHG emissions by 21.9 million tons, or the equivalent to removing 3.5 million cars and pickups from America’s roadways.
The cost of E85 fluctuates depending on supply and market conditions. In April 2011, E85 had a lower average price per gallon than regular gas for all regions of the United States.
The issues related to E85 are reduced fuel efficiency – 25 percent to 30 percent fewer miles per gallon – and E85 pump availability. According to the National Ethanol Vehicle Coalition (NEVC), there are approximately 2,600 retail stations (out of 160,000 stations nationwide) offering E85 across the country. This number is expected to grow significantly due to many federal and state incentives that encourage ethanol production and use and E85 station development. In addition, the U.S. Department of Agriculture’s (USDA’s) Rural Energy for America Program (REAP) provides grants and loan guarantees for the installation of retail flexible fuel pumps and related equipment, and the retrofitting of existing pumps to dispense E85. Industry commitment to increase the number of available E85 stations is also strong, and the science community is confident that further development in more efficient methods of E85 production will lower the production cost of this renewable fuel.
In the U.S., 90 percent to 95 percent of all ethanol is made from corn. There are approximately 204 ethanol biorefineries in the U.S., with 9 under construction. The horizon points toward using cellulose-based ethanol and the commercialization of technologies using cellulose feedstocks is beginning to emerge. There are more than 20 advanced and cellulosic ethanol projects under development and construction in the United States. According to the U.S. Dept. of Energy’s Argonne National Laboratory, cellulosic ethanol offers an 85 percent reduction in GHG emissions on a per gallon basis.
While industry believes ethanol will be an important part of the energy solution, it can’t do it alone. Hybrids, electric and fuel-cell cars will need to be in the mix.
For more information:
|SAE (Society of Automotive Engineers) International:
Technical Paper on leak-testing hazards when using “air” instead of an inert gas,
such as nitrogen.
For Ethanol (E85) vehicles: http://papers.sae.org/2008-01-0554
SAE (Society of Automotive Engineers) International:
Technical Paper on Fuel Tank and Charcoal Canister Fire Hazards during EVAP System Leak Testing.
For Gasoline vehicles: http://papers.sae.org/2007-01-1235
|American Coalition for Ethanol (ACE):
The American Coalition for Ethanol promotes the production and use of ethanol – America’s renewable fuel.
Ethanol is a biofuel made from corn and other crops and, soon, from cellulosic sources like switchgrass.
|National Ethanol Vehicle Coalition (NEVC):
Helping fuel marketers learn more about selling blends of ethanol by installing ethanol blender pumps
|Renewable Fuels Association (RFA):
Renewable Fuels Association (RFA) has been the authoritative voice of the U.S. ethanol industry.
|United States Dept. of Energy:
The official U.S. government source for fuel economy information.
|United States Environmental Protection Agency:
Our mission is to protect human health and the environment.
|United States Dept. of Energy, Alternative Fuels & Advanced Vehicles Data Center:
The AFDC is a resource of the U.S. Department of Energy’s Clean Cities program.