California regulators have updated their proposal for limiting greenhouse gas emissions from automobiles, making the planned standards stricter for cars and small trucks and slightly less stringent for large trucks and sport-utility vehicles.
Manufacturers also would be given two additional years to fully comply with the new requirements.
The California Air Resources Board (CARB) staff unveiled the updated proposal Aug. 6. The limits would be phased in beginning in 2009.
The report also outlines technology packages that the state believes auto makers could use to achieve the greenhouse gas reductions.
Under the updated proposal, cars and light trucks would need to trim emissions by 34 percent when the standards are fully implemented in 2016. Larger trucks and SUVs would need to trim emissions by 25 percent once the standards are fully in place. The original proposal, released June 14, called for emissions reductions of 30 percent for cars and light trucks and about 21 percent for larger trucks and SUVs.
The phase-in period begins in 2009.
The amended rules extend from 2014 until 2016, the time by which car manufacturers must comply with the final standards. The original deadlines were set based on the amount of time it takes Japanese car companies to design and build vehicles, but California officials decided to extend the deadlines to assist American manufacturers that typically take longer, said CARB spokesman Jerry Martin.
``We move to a timetable that really allows the car companies to design and build cars the way we want them done,'' Mr. Martin said.
The regulations are expected to add an average of $626 to the cost of a car and $955 to the cost of a large truck or SUV, according to California estimates. However, auto makers have said the costs could be much higher.
The Alliance of Automobile Manufacturers, which represents car makers, has said California is exceeding its authority by trying to set its own fuel economy standards. The group also said it would consider legal action to try to stop the new rules from taking effect.
Spokesmen from the alliance could not be reached for comment.
The California Air Resources Board has scheduled a public hearing on the proposal for Sept. 23 in Los Angeles. If the board approves the proposal, it will be sent to the state legislature for its consideration.