Labelled an environmentalist-come-lately when running as a candidate for governor of California, Arnold Schwarzenegger answered his critics by announcing plans to retrofit one of his petrol-guzzling Hummers to run on eco-friendly hydrogen power.

“I think that’s where the future of fuel will be going,” he said at the time, according to Associated Press (AP).

But seven months later, the high-tech Hummer has yet to hit the road and, for the moment, the project has produced more talk than torque, the report said.

AP said seven companies have submitted bids to do the work, ranging in cost from $US40,000 to $150,000, but no contract has been signed, according to Rick Margolin, assistant director of Energy Independence Now, a Santa Monica group that evaluated the proposals on behalf of the governor.

“He does have people working on it,” Margolin reportedly said.

AP said Schwarzenegger raised his proposal for a clean-fuel vehicle with officials in the Hummer division of General Motors but for now the company is not engineering a hydrogen-fuelled Hummer for him or anyone else.

“It’s out there as an idea,” David Caldwell, a spokesman for Hummer, told Associated Press, adding: “It’s not something that exists currently. It’s not something you would expect to see in the near future.”

He reportedly said: “We would never do a Hummer on any energy source that would not perform like a Hummer is supposed to perform.”

AP noted that movie star Schwarzenegger took delivery of the first Hummer made available to the public more than a decade ago.

His popularity in Hollywood helped transform the brand into a favourite status vehicle but he was forced to defend his association with the hulking, poor fuel economy Hummer during the California state governor campaign when rivals questioned his environmental credentials considering his choice of transportation, the report said.

AP said General Motors markets and distributes the latest version of the vehicle, the 6,400-pound (2,880-kilogram) H2, and estimates it gets 10 to 13 miles per gallon while dealers put the figure at 8 to 10 mpg.

The issue hasn’t vanished, AP said, noting that activists plan a Thursday news conference in state capital Sacramento to urge the governor to stop driving his signature vehicle, citing its impact on air quality.

Sierra Club lobbyist Bill Magavern reportedly said the petrol-greedy Hummer “wreaks havoc to our environment” but viewed the governor’s promise to retrofit his sport utility vehicle as “largely irrelevant.”

“The Hummer is the opposite kind of vehicle from what we would like to see on California streets,” he told Associated Press, adding: “What’s more important to us is whether he keeps his promise to reduce California air pollution by 50%. … We have yet to see his strategy.”

AP noted there was no mention of his Hummer on Tuesday, when Schwarzenegger directed state agencies to work with private companies and research groups to develop a statewide network of stations offering hydrogen fuel within six years: “Your government will lead by example,” he reportedly said in announcing the initiative.

With the governor working on the alternative-fuelling plan, the retrofitted Hummer was “pushed down on the priority list,” Margolin told Associated Press.