New renderings and some specifications for the hybrid-electric U.S. Army tank that's been in the works for more than four years have been revealed.

BAE Systems, which demonstrated the first hybrid-drive ground-combat vehicle (GCV) in August 2007, says the tank is as much as 20 percent more fuel-efficient than conventional diesel-powered tanks and is quicker – relatively speaking, of course – off the line. The 70-ton tank has room for 12.

BAE, whose Michigan and California designers worked on the project, is developing the tank for the U.S. Army as part of what the military calls its Future Combat Systems (FCS) program. *UPDATE: This program was canceled by the United States Army in 2009. With hybrid powertrains, the Army is looking to use hybrid tanks as a way for fewer fueling supply lines – and fewer lives at risk as a result – to be required to keep the vehicles going. Since the average Army soldier uses 22 gallons of gasoline a day, the military has quite an incentive to reduce fuel usage.