In California, where clean-air rules make gasoline more expensive, prices could approach $2 a gallon.

Gasoline fell on weak demand for gas that would fail new clean-air rules.

The car would qualify as a zero-emission vehicle under California's clean-air rules.

Instead, the Administration will begin what an official called a "wide open process" of examining how it applies clean-air rules to imported gasoline.

Some business people have adapted to the clean-air rules.

Tough clean-air rules are about to be approved in California, promising an immense impact on cars and fuel.

It would be ready - nay, eager - to comply with stringent clean-air rules wherever they were imposed.

Some opportunistic politicians have blamed the state's strict clean-air rules, which they say deterred construction of new power plants and shut older ones down.

At the same time, New Jersey and nine other states are suing the federal government, arguing against a proposed relaxation of clean-air rules.

Bush administration eases clean-air rules for utilities and industry.