US express delivery service UPS has confirmed it is to deploy its first three large package delivery vehicles utilizing zero-emission hydrogen fuel cells, following the success of initial road-test results and the emergence of significant technological advancements.

The announcement was made during a press conference in Los Angeles to launch the first of the Dodge Sprinter vans to be deployed.

"Our two test programmes showed the on-road reliability of fuel cell vehicles is excellent, equivalent to our current fleet," said Chris Mahoney, UPS senior vice president of global transportation services. "But what's truly exciting is how fast the technology is progressing."

Representatives of the clean vehicle manufacturer DaimlerChrysler, who constructed the vans and helped carry out initial testing, and the Environmental Protection Agency (EPA) and the Department of Energy and the state of California, who helped to fund and promote the venture, were also present.

According to DaimlerChrysler, the new fuel cell Sprinters feature a 20 per cent increase in powertrain efficiency compared to the first Sprinter tested by UPS; a 40 per cent increase in range to 155 miles, and a 45 per cent increase in peak engine power, with a similar acceleration as a gasoline- or diesel-powered UPS vehicle.