But the practical impact of the announcement on the fuel blend, known as E15, was not clear.
The generators that remain are new, upgraded versions, the producers said, that are less noisy and run on a cleaner biodiesel fuel blend.
The Audi R10 TDI ran on a fuel blend including second generation biomass-toliquids fuel (BTL) made by Shell from non-food biomass, such as waste wood.
At issue is E15, the fuel blend consisting of 15 percent ethanol and 85 percent gasoline, rather than the typical 10-percent, 90-percent formulation, E10.
Critics of the fuel blend, which contains 15-percent biofuel composed primarily of corn-based ethanol, claim it could damage older engines.
The federal government offers ethanol producers a subsidy of 51 cents per gallon (13.5 cents per litre); and a growing number of states are pushing for wider use of E85, a fuel blend that is 85% ethanol and only 15% petrol.
A new engine-durability study that found damage in engines run on gasoline with 15-percent ethanol content proved one of two things: either the Environmental Protection Agency was hasty in authorizing the sale of the fuel blend or the study's authors produced "junk science," in the words of one critic.
Backed by government subsidies and mandates, hundreds of ethanol plants rose among the golden fields of the Corn Belt, bringing jobs and business to small towns, providing farmers with a new market for their crops and generating billions of dollars in revenue for the producers of this corn-based fuel blend.
TALK of alternative fuels, especially ethanol and biodiesel, seems to be everywhere: in the "state of" speeches from Gov. George E. Pataki and President Bush this year, in the automakers' marketing pushes, and even from the country singer Willie Nelson, who has lent his name to a new fuel blend called BioWillie.
Therefore, the carbon number distribution of the jet fuel blend has a significant effect on the viscosity of the blend.
With chemical upgrading, 22 of the 33 compounds could have potential as jet fuel blend components.
