"Absolutely a great thing for Utah air quality," the director of the state's Division of Air Quality said of the prospect of improving vehicle fuel efficiency.

Rick Sprott was commenting on Tuesday's approval by the U.S. Senate Committee on Commerce, Science and Transportation of a bill that would set standards of 35 miles per gallon for passenger cars and light trucks by the year 2020. The measure, which has faced some controversy, is expected to reach the full Senate in June.

The Ten-in-Ten Fuel Economy Act, SB137, is sponsored by Sen. Dianne Feinstein, D-Calif., who is not a member of the Commerce Committee.

The bill also would require that after 2020 and until 2030, fuel economy increase by at least 4 percent a year.

Present standards require that new passenger cars achieve 27.5 mpg, according to the National Highway Traffic Safety Administration. The standard has not changed since 1990.

Sprott said that besides saving fuel, improving mileage also benefits air quality.

The biggest source of air pollution along the Wasatch Front is what comes out of tailpipes. According to the Environmental Protection Agency, vehicles release non-methane organic gases, particulates, carbon monoxide and nitrogen compounds.

"From our viewpoint, any work to improve acreage mileage of vehicles ... is certainly a very important thing for Utah air quality," Sprott said.

He added that the EPA has enacted new vehicle rules that also will help knock down air pollution in the state. The rules cover light-duty cars and trucks and heavy-duty diesel equipment used off the highways. The rules require stringent fuel controls, such as using low-sulfur fuel.

Besides these, he said, the EPA has proposed new air controls for railroad locomotives and diesel ship engines.

The new and proposed EPA regulations should "reduce some of the important pollutants" that create ozone and release particulates, both of which are problems along the Wasatch Front, he said.

According to Sprott, the reduction eventually could be "as much as 80 percent. That's a really big deal."

When this is combined with great improvements in vehicle mileage, he said, the regulations improve Utah's air quality.

Joining the chorus of praise was Mark Clemens, manager of the Sierra Club's Utah chapter, based in Salt Lake City.

"This is actually great news," he said. "Congress has finally discovered the richest place to drill for oil, and that is the fuel efficiency of our automobiles."

Clemens said millions of barrels of oil could be saved by implementing common-sense improvements to the country's vehicles.

The change would be good for clean air, too, he said.