HONEOYE FALLS, N.Y. (AP) – General Motors Corp. rolled out the world’s first drivable fuel cell truck Friday and handed over the keys to an exacting patron: the Army.

The olive-green pickup took a demonstration spin around GM’s fuel-cell development center in rural upstate New York, carrying Sen. Hillary Rodham Clinton and Brig. Gen. Roger Nadeau, commander of the Army Research, Development and Engineering Command.

The modified Chevrolet Silverado crew-cab truck will be leased to the Defense Department for noncombat uses at Fort Belvoir, Va., and Camp Pendleton, Calif., and tested in various climates and terrain around the country until July 2006.

Its electric engine emits a high-pitched whine, but a key feature in future fuel-cell models developed with the military will be stealth – along with better fuel consumption and zero tailpipe emissions.

Instead of gasoline, the fuel cells run on energy produced when hydrogen and oxygen are mixed, and the only byproduct is water vapor.

Since 2003, President Bush has pushed a five-year, $1.7 billion research program to develop hydrogen as an energy source. Most major automakers are developing hydrogen fuel cells, but cost and a lack of fueling stations make the vehicles unmarketable for now.