UPS is adding 245 new delivery trucks powered by compressed natural gas to its fleet in Colorado and California, expanding its use of CNG vehicles more than 20 percent.

The trucks deployed this month in Denver and in four California cities joined more than 900 CNG delivery trucks already in use by UPS worldwide, the company said.

The new CNG trucks will emit 15 percent less pollution than the cleanest diesel engines available today, UPS claims. The trucks look no different from the typical UPS brown delivery truck, except for decals marking them as CNG-powered vehicles.

UPS now has more than 1,900 trucks in its "green fleet," powered by a variety of alternative fuels, including CNG, liquefied natural gas, propane, electric and hybrid electric vehicles. It's experimenting with hydrogen fuel cells for trucks as well.

"The greening of our fleet demonstrates the effectiveness of harnessing multiple technologies and applying the right vehicles," said Bob Stoffel, UPS senior vice president of supply chain strategy, engineering and sustainability.

Buck