WASHINGTON -- A federal appeals court panel today overturned government fuel economy standards for light trucks in the 2008-11 model years.
The three-judge 9th U.S. Circuit Court of Appeals panel in California ruled that the standards didnt properly assess the risk vehicles pose to the environment.
The standards were considered innovative in that they set different fuel economy targets for vehicles of different sizes.
Overall, automakers were to improve light-truck fuel economy from 22.2 mpg in 2007 to about 24 mpg by 2011.
But in the lawsuit, some states and environmental groups that want tougher standards said the National Highway Traffic Safety Administration failed to account for the threat of carbon dioxide emissions in doing cost-benefit analyses.
CO2, a byproduct of burning fuel, is considered to be the most prevalent greenhouse gas, contributing to global warming.
The panel ordered NHTSA to write new rules "as expeditiously as possible and for the earliest model year practicable."
Dave McCurdy, president of the Alliance of Automobile Manufacturers, warns that further changes in the 2008-11 standards could have the adverse effect of delaying automakers' progress in improving fuel economy.
"Announced more than 19 months ago the 2008-2011 light truck fuel economy rule represented the largest fuel economy increase in the history of the CAFE program," he said in a statement. "It has become the basis for product planning through 2011.
"Any further changes to the program would only delay the progress that manufacturers have made towards increasing fleet wide fuel economy."
A spokesman for the Justice Department said the Bush administration is considering "all its options" in the matter.