"We are excited about the new green technologies that are being developed in the United States and produced in UAW-represented facilities," King said in testimony for representatives of both the U.S. Environment Protection Agency and the National Highway Traffic Safety Administration at a hearing in Detroit.
"These proposed rules will reduce the pollution that contributes to climate change, significantly reduce America's dependence on foreign oil and save American families money at the pump," King said.
The Detroit News quoted King as saying tougher fuel standards "will also create jobs in the auto industry and throughout the economy."
The Obama administration has proposed raising the average fuel efficiency of vehicles sold in the United States to 54.5 mpg by 2025.
The proposal also has support from automakers. In part, news analysts have said, automakers are afraid of coming across as ungrateful, given the multibillion-dollar bailouts of General Motors Co. and Chrysler Group LLC, both of which went through bankruptcy in the summer of 2009.
"Clearly, this proposal represents a dramatic attempt to advance the mutual goals of CO2 reduction and increased energy diversity. We welcome the opportunity to work with the agencies as they finalize the proposed regulations," said Michael Robinson, vice president for environment, energy and safety at GM.
At least one important industry group stands opposed, however.
Don Chalmers, president of the National Automobile Dealers Association said the price of vehicles would rise higher than expected.
"The proposals drastically underestimate the cost impact on new vehicles," he said.
He also complained that the additional costs would impact lower-income customers more than those with higher incomes.
"That's the reality of vehicle financing today," he said.