General Motors' goal of selling commercially viable hydrogen fuel cell-powered vehicles by 2010 looks to have come a step closer following rigorous testing of the US car manufacturing giant's pollution-free HydroGen 3 vehicle.

The car, which has a range of around 250 miles, was subjected to what is regarded as the most rigorous stop-and-go test drives in the world along a FedEx Express route in downtown Tokyo, Japan.

GM formed a partnership with FedEx for the yearlong series of tests on the HydroGen 3, which also became the first hydrogen-fuelled vehicle approved for use on public streets in Japan.

"What better test could you find than in downtown Tokyo for intense driving conditions?" asked Pete Barkey, manager of GM fuel cell communications. "We've seen how the vehicle performs under high temperature extremes, through stops and starts and idling times.

"Every program and every testing of this type does help get the technology ready quicker," he said.

Several types of fuel cell produce electricity by combining hydrogen and oxygen over a platinum catalyst.