Adding more ethanol to gasoline may help the U.S. meet a Congressional mandate to use more of the renewable fuel, but it could damage many of the cars now on the road, say automakers.
Last year, U.S. vehicle manufacturers went public with their alarm that the EPA might increase the permissible ethanol in standard "gasoline" to 12 or even 15 percent.
Now, in light of news that the U.S. Environmental Protection Agency (EPA) will issue a long-delayed rule approving up to 15 percent ethanol in gasoline, carmakers are ramping up a counteroffensive.
Fear of failures
Their fear is that mechanical components on older vehicles, which were never designed for higher percentages of ethanol, will fail--leaving them in the cross-hairs of customers angry that their cars couldn't run on a fuel they were not intended to use.
Vulnerable components include engines, fuel pumps, and various rubber seals. The Alliance of Auto Manufacturers says that half the engines it tested had problems on blends with higher amounts of ethanol.
Extra oxygen atom
One problem lies in the engine-control system, which monitors the oxygen content of the exhaust and uses it to control the mixture of fuel and air. Because ethanol molecules have an extra atom of oxygen, the system may reduce the fuel content to compensate.
That would make the engine run hotter, which can damage the catalytic converter that controls emissions--making the car's exhaust dirtier overall. It could also trigger the car's "Check Engine" light, requiring a service visit.
Different pumps for different model years?
The EPA's proposed rule only applies to vehicles made in 2001 or later, but how it will propose that be implemented at the pump--different nozzles depending on your car's model year?--is entirely unknown.
The carmakers' concerns are echoed by makers of other types of engines, including those for boats, motorcycles, snowmobiles, all-terrain vehicles, and even power equipment. The Union of Concerned Scientists also opposes the EPA's proposed rule change.
Today's gas: actually E10
Since 1978, new cars have been able to run on gasoline with up to 10 percent ethanol. Much of the gas sold in the U.S. is now actually a blend: 90 percent gasoline, 10 percent ethanol. It's known as E10, for the percentage of the total derived from the corn-based biofuel.
On average, U.S. fuel today contains roughly 8 percent ethanol. The Renewable Fuels Association reports that 9 billion gallons of ethanol were produced here in 2008, triple the level of 2003 but still a long way from the Congressional mandate of 15 billion gallons by 2015.
Different from flex-fuel
So-called flex-fuel vehicles, however, have the ability to run on gasoline, ethanol (sold as E85, or a blend of 85 percent ethanol and 15 percent gasoline), or any mixture of the two.
Domestic automakers have slowly been increasing the percentage of their new cars with flex-fuel capability. Ford will have doubled its flex-fuel vehicle production by the end of this year, and every 2011 Buick Regal will offer flex-fuel capability as standard.
But E85 ethanol fuel is not widely available in the U.S. today. It can be purchased at slightly more than 2,000 filling stations, or just 1.5 percent, most of them concentrated near ethanol refineries in the agricultural Midwestern states.