The Bush administration sided with Detroit's automakers in a court challenge to California's zero-emissions vehicle mandate on Oct. 9, according to an article in The Detroit News. Justice Department officials argued that California's ZEV mandate intrudes on the federal government's exclusive authority to set fuel economy standards. Automakers and environ-mental groups are watching the California legal battle, with the state's ability to set tougher air pollution standards at stake. The case is being heard in the 9th U.S. Circuit Court of Appeals. California is appealing an injunction that blocked enforcement of its ZEV mandate. Since 1990, California Air Resources Board rules have required the sale of ultra-clean vehicles with little or no emissions. In 2001, the board adopted several changes to its program to promote the advancement of more promising clean-air technologies, like hybrid-electric vehicles and fuel-cell powertrains. California officials argue the Air Resources Board rules fall within the authority of the state to set pollution standards under the federal Clean Air Act. But in June, a federal judge in Fresno, CA, ruled that incentives in the California plan that allow automakers to sell highly fuel-efficient cars was tantamount to a fuel economy mandate. California has since abandoned plans to enforce the ZEV mandate until 2004, at the earliest, and the Air Resources Board will consider other changes in 2003.