The chief of staff of the Army is celebrating progress on a new generation of Abrams tank that he said is lighter, more advanced and on track to be delivered years ahead of schedule. Speaking at an event hosted by the Association of the United States Army on Tuesday, Gen. Randy George touted the M1E3 , which last week made its debut as a pre-prototype at the Detroit Auto Show. “Obviously, not as fast as the Chevy ZR1,” George said, referring to the flashy Corvette also on display at the show. “