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Biofuels may be hazardous to your car’s health

Frustrated with pumping gasoline that costs well over $3 a gallon, a collection of cheaper biofuels are tempting U.S. drivers. But experts warn they may lead to long-term damage to a vehicle’s engine if not properly maintained.
Alternative Fuel Sources Gain In Popularity
Diesel car owners fill up canisters with biodiesel fuel at the Biofuel Oasis station in Berkeley, Calif., earlier this month. With gas prices rising, drivers are looking for alternative ways to fuel their cars.David Paul Morris / Getty Images file

With gasoline prices ticking higher all this year and the impact of Hurricane Katrina driving them ever higher, a growing number of Americans are turning to alternative fuels to power their vehicles. But experts warn that simply filling up with these unconventional fuels could end up costing you down the road if you're not careful.

Frustrated with pumping gasoline that costs well over $3 a gallon, some U.S. drivers are turning to a collection of biofuels including E85, a mixture of 85 percent corn-based ethanol and 15 percent gasoline, and biodiesel, an alternative to petroleum-based diesel made from renewable sources such as vegetable oils or animal fats, into their cars.

These sustainable fuels are cleaner in terms of emissions than conventional gasoline, their advocates say, and their widespread use could ease U.S. dependence on Middle Eastern oil.

But despite the obvious benefits of alternative fuels, car experts caution that there are some hidden drawbacks. A quick switch to E85 or biodiesel, if it is done without enough research and preparation, can cause more harm than good, these experts say. Specifically, an older car may suffer from worn-out gaskets, or lasting damage to a gasoline tank or a vehicle’s overall fuel system.

“It all comes down to lubrication, corrosiveness and viscosity,” said Stanley P. Miller of the Alternate Fuel Project Center. “You can get problems if you haven’t replaced parts of your vehicle that are not compatible with the new fuel you’re putting in your car.”

Millions of modern cars steer clear of these pitfalls, as they are so-called “flexible fuel” vehicles designed to run on biofuels like E85, which although it is only available in selected gasoline stations, chiefly in Midwestern agricultural states, runs about 30 cents cheaper than regular gas.

But although the number of E85 filling stations nationwide is rising, many consumers who buy flexible fuel vehicles are not even made aware of the capability notes Dan Kahn, a road-test editor at online automotive resource

“Lots of cars, like the GM passenger vehicles and Mercedes Benz E Class, are qualified to run the E85 fuel blend, but their owners don’t know it,” Kahn said. But on the other hand plenty of cars are not qualified, he added, and so it’s important for car owners to check their owner’s manual, or with a dealer, before using the fuel, as cars not tagged as flexible fuel vehicles that use E85 risk damaging their engines.

E85 is predominantly made up of ethanol, or grain alcohol, which is a solvent and can corrode “soft” parts inside the car’s engine, such as gaskets, seals and fuel injectors quicker than gasoline Kahn said. Also, unlike gasoline, alcohol is not a lubricant and so these engine parts will need to be replaced more often than usual he noted.

“This is not something that would happen right away, but it’s possible over time, and a lot of flexible fuel vehicles are designed so they can handle this,” Kahn said. “But it’s still a good idea to change fuel filters whenever it’s recommended, and make sure your oil is changed and your car is tuned up regularly. In the end, if you follow a manufacturer’s guidelines on this you shouldn’t have too much of a problem,” he added.

Another potentially more destructive consequence of using ethanol-based fuel is permanent damage to a car’s gasoline tank, notes Dr. Timothy Maxwell, a professor of mechanical engineering at Texas Tech University’s Mechanical Engineering Department.

“Water is attracted to alcohol, and so with a metal fuel tank, especially one that’s made of steel, the ethanol in the fuel absorbs water from the atmosphere and water droplets form,” said Maxwell. “That can lead to rust and corrosion in the tank, and pin holes can form.”

Also potentially harmful for a car’s engine is the sediment that naturally builds up in a gasoline tank says Kahn.

“This is especially true of an older vehicle,” he said. “If you have a Ford pickup truck, for example, with about 50,000 miles on the clock, it’s going to have some stuff forming in the tank, and ethanol-based fuel, and more importantly biodiesel, has solvent properties that dissolve that stuff and ‘clean’ the gas tank, and it can get sucked into fuel lines and cause problem in engine — this is why important to keep changing your fuel filters.”

Maxwell also notes that, while some users of E85 claim to use the fuel in their cars without any problems, older, non-flexible fuel cars must be converted to run on the fuel. More alcohol than gasoline is needed to power a car’s engine, and so a car’s computer has to be reprogrammed to compensate, he notes. Without this adjustment, a car’s engine will have a poorer performance rate and a dirty exhaust he said.

“Converting a car to burn ethanol is not something an ordinary homeowner can do — it takes someone who knows what they are doing,” he said. “And spending to modify an engine to burn ethanol can mean you spend more than the fuel cost saving you’ll get.”

Similarly, flexible-fuel vehicles ready to run on both gasoline and biofuels like E85 typically do not run as efficiently as an engine designed to use a specific type of fuel, Maxwell said.

“Until you can buy a car that runs on a biofuel at your local car dealer the alternative fuel market won’t be a good thing for the general public; it’s not just simple thing to switch over and it’s too complex for most people to consider doing,” Maxwell said. “The other thing about fuel is its availability. It would be nice if we all had ethanol in our local gas station, but it’s not available everywhere. I think there’s a future for all this stuff, but has to become more organized than independent actors doing conversions of their cars.”