The Obama administration's new auto-emissions rules will be individualized for each car class and company, detracting from current law that sets a single standard for the entire U.S. fleet, a senior administration official said Monday night.

The new rules will be designed to lead to an overall average of 39 mpg for cars and 30 mpg for trucks by 2016, with a fleetwide standard still in place, the official said. But by also setting standards for each class size and manufacturer, auto makers won't be able to ramp up the efficiency of select models while avoiding improving others, such as SUVs, the official said.

"Every single category of cars has to become more efficient," said the official, briefing reporters on a conference call on the condition of anonymity.

The new standards, which will also set rules on the reduction of greenhouse-gas emissions, mean that the overall average of cars and light trucks on U.S. roads will be 35.5 mpg by 2016, four years earlier than current federal law requires. The standards will be developed jointly by the Transportation Department and Environmental Protection Agency, the official said.

The new standards also resolve a dispute between the auto industry and California, which is seeking a waiver from the federal government to set its own rules on greenhouse-gas emissions from vehicles. California officials have agreed to defer to the national standard if they win the waiver, the Obama administration official said.

The rules will increase the cost of manufacturing a vehicle by $600, the official said, acknowledging that consumers will, too, end up paying more for cars. But because the cars will burn less fuel, the added initial cost will be offset by gasoline savings, the official said.

The official called the new standards "historic," in part because for the first time they would require a massive reduction in greenhouse-gas emissions, which are blamed for global warming. The environmental benefits under the new rules would be equivalent to taking 177 million cars off the road, the official said.

The administration developed the standards on the assumption that a gallon of gasoline will cost $3.50 in 2016.

The new rules represent a partial victory for auto makers, who have called for a single national emissions and fuel-economy standard rather than a "patchwork" of state-level and federal rules.

General Motors Corp. (GM) said in a statement Monday night it was "fully committed to this new approach."

"Harmonizing a variety of regulations will benefit consumers across America by getting cleaner, more efficient vehicles on the road quicker and more affordably," the company said. "In turn, GM and the auto industry benefit by having more consistency and certainty to guide our product plans."

Ford Motor Co. (F) said it was "pleased that President Obama is taking decisive and positive action as we work together toward one national standard...."

-By Josh Mitchell, Dow Jones Newswires; 202-862-6637; joshua.mitchell@dowjones.com