The proposed 54.5 mpg rule could create 100,000 new jobs, according to UAW Pres. Bob King.

The United Auto Workers is out to mend its once-robust ties to the environmental movement.

In the past, the union had opposed raising fuel economy standards because it feared higher standards for trucks could lead to the elimination of jobs. During much of the last three decades, the union had been persuaded that changing the fuel-economy standards would weaken the domestic carmakers’ tight grip on the US truck market.

The union reversed its position in 2009 under pressure from the Obama administration, which was in the midst of bailing General Motors and Chrysler.  But this time the union voluntarily teamed up with various environmental groups to support new standards that will boost federal fuel-economy standards.

UAW President Bob King said Tuesday that he is convinced the new standards, which will raise fuel standards for automaker to 54.5 miles per gallon by 2025, will help create new jobs in the U.S. by promoting new technology.

“The proposed rules are sensible, achievable, and needed,” King said, adding “the incremental increase in the price of a vehicle will covered by the money consumes will save by using less fuel,” added King, who cited UAW legend Walter Reuther’s dictum that it not only wanted clean factories, it also wanted clean lakes.

King also said in the past the union has to reestablish its ties to groups in the environmental movement to bolster its overall position in American society.

“They are good for the auto industry and its workers, good for the broader economy, good for the environment and good for our national security,” said King. “The drive to bring innovative fuel-saving technologies to market is transforming the auto industry in the United States and creating good jobs from the research lab to the factory floor.”

King said proposed standards to increase fuel economy and reduce tailpipe emissions have broad economic and social benefits and enjoy wide public support – a position echoed by environmental leaders during testimony in Detroit.

The proposed rules also take into account the importance of specialized vehicles such as big up trucks, which are vital to domestic manufacturers.

King joined several environmental, industry, educational and citizen groups to testify before the U.S. Environmental Protection Administration and the National Highway Traffic Safety Administration about new standards proposed by the Obama administration.

“With these rules in place, there’s a much smaller chance you’ll see ugly pictures of beautiful birds covered in petroleum,” said Larry Schweiger, CEO of the National Wildlife Federation.

“We’ll reduce greenhouse gas pollution by 2 billion tons, and cut our consumption of oil by 3.4 million barrels a day. That will reduce the need for risky drilling in fragile habitats,” Schweiger said.

David Foster, Executive Director of the BlueGreen Alliance, a partnership between U.S. labor unions and environmental organizations, said: “These standards are moving America to a clean energy economy that creates good jobs that are also good for our environment.

“2012 is expected to be the third straight year of double-digit auto sales growth for the US, with many consumers upgrading their older vehicles for cleaner cars now available on the market. The 54.5 miles per gallon standard will continue to fuel that comeback for years to come,” said Foster.

The Detroit hearings brought out some dissenting opinions from the likes of Don Chalmers, a New Mexico Ford dealer who served as a representative for the National Automobile Dealers Association.  He cautioned that federal regulators avoid “rushing headlong” into new rules that could have unintended consequences.

On a financial front, Chalmers argued that the new CAFE rules will bump monthly payments up by $60 to $70 a month and, perhaps more concerning, result in vehicles that buyers won’t want.

“If the customers don’t want to buy these products, we all lose,” he cautioned.

The proposed rules, which will modify standards already set to rise to 37.5 mpg by 2016, have caused a split within the auto industry itself.  General Motors, Toyota and Hyundai are supporting the change, the Korean maker’s U.S. CEO John Krafcik telling TheDetroitBureau.com, “Of course, we’re positive on it.”  But several makers, including Volkswagen and Daimler, have refused to lend their support.

Paul A. Eisenstein contributed to this report.