General Motors Corporation and Shell Oil Company announced plans yesterday to bring a small fleet of hydrogen-powered automobiles to the metro-New York area.

However, the average consumer shouldn’t expect to be driving one of these pollution-free automobiles anytime soon.

GM plans to provide 13 fuel-cell-powered vehicles to an undetermined commercial fleet owner, and Shell Oil plans to establish the state’s first hydrogen service station at an existing Shell station in New York City sometime in 2006.

Unlike gasoline-powered automobiles, hydrogen-powered vehicles emit only water.

“This fleet will put New York in the forefront on the road to the future,” said the vice president of GM research and development and planning, Lawrence Burns, at a press conference yesterday at Tavern on the Green.

The two companies unveiled a similar initiative in November in Washington, D.C., where there are six hydrogen-powered vehicles in operation.

Five of those vehicles are being used as test-drive vehicles by politicians, educational groups, and business leaders.

“We felt that anyone weighing into that [national energy] debate needed to kick the tires of a real hydro-powered vehicle,” said Mr. Burns.

The postal service is using the sixth vehicle.

The letter carrier driving GM’s hydrogen-powered automobile, Steve Yates, said it handles no differently from a regular gasoline-powered automobile.

“I haven’t been out on the highway with it, but I’ve had no problems accelerating, pulling out into traffic, or stopping,” said Mr. Yates, estimating he has driven as fast as 40 miles an hour in the automobile.

GM asked the postal service to test the vehicle to see how it performs under the stress of stopping and starting all day on a delivery route.

GM also has three so-called Hydro-Gen vehicles in operation in California.

The Washington and New York hydrogen stations are intended to be the first in a string of stations between the two cities, creating an East Coast corridor from which GM and Shell plan to collect data as they develop the automobile technology and the infrastructure to service them.

It cost about $2 million to build the Washington station, according to the chief executive of Shell Hydrogen, Jeremy Bentham.

GM’s goal is to be able to create hydrogen-powered vehicles that are comparable in durability, performance, and price to gasoline-powered vehicles by 2010.

“Fuel cells are real, the technology is real, it’s just not yet affordable,” said Mr. Burns. “This is a technology moon shot.”

Indeed, significant consumer usage of these vehicles is probably decades off.

Mr. Burns estimated that GM will have to produce between 500,000 and 1 million vehicles a year in order for them to be commercially viable.

Mr. Bentham estimated there will have to be 12,000 hydrogen stations nationwide in order for the fuel to be conveniently available.

By contrast, hybrid vehicles that run on a combination of electricity and gasoline are much further along. The auto industry reported that 84,000 hybrids were sold in American last year. J.D. Power and Associates estimates that 220,000 will be sold this year.

In other news, Ford Motor Company yesterday announced it is recalling 792,000 sport utility vehicles because of a fire risk from a speed-control switch.