"Having the oil companies compete over who can produce the cleanest gasoline is great."

They also said that so far, the House bill had only a weak provision for requiring cars to burn cleaner gasoline.

Scientists say Pemex must move more quickly, and openly, to make much cleaner gasoline for the capital all year round.

Further, prices are often higher still in big cities like Chicago, where government requires cleaner gasoline as a pollution-control tool.

Supporters of the deal also say that the higher California prices are primarily caused by taxes, a requirement for special clean gasoline, and other factors.

In an attempt to stay ahead of the legislators, the major oil companies are already selling somewhat cleaner gasoline.

Some, he said, are not automatically required to switch to cleaner gasoline but could choose to do so.

Energy prices fell sharply after 28 Pennsylvania counties were allowed to pull out of a program using a cleaner gasoline.

When soaked with clean gasoline, chamois will not allow water to pass through its surface fibers.

The rule requiring cleaner gasoline will make it easier for the car manufacturers to meet their new targets.