New Jersey Transit (NJT) unveiled yesterday the first hybrid electric cruiser bus in the nation and its first hybrid electric transit bus. With help from a battery pack, the cruiser bus hybrid, manufactured by MCI, uses two electric motors to supplement the output of a smaller diesel engine. The electric motors also serve as alternators to recharge the onboard battery pack as the bus coasts downhill or approaches a stop. The blending of power from the diesel engine and the electric motors allows the diesel engine to operate at its most efficient speeds. The transit bus hybrid electric system, designed and built by ISE Research of San Diego, Calif., allows a 13-ton bus to use the same engine as a 3.5-ton pickup truck. Supplemented by the battery pack, a diesel engine-driven generator provides electricity for the motor. As part of the largest modernization program in its history, NJT invested $8.5 million in federal funds for seven hybrid electric buses that include four cruiser buses for intercity routes and three transit buses for use on local routes.