Vickers has offered a new export version of the Challenger-2 tank which is in many ways superior to the model in British service. (Only Oman bought the original Challenger-2.) The new Challenger-2E uses the EuroPower Pack 1500hp engine, which provides better speed and acceleration. As this is smaller than the original engine, it provides room for more fuel and for an Auxiliary Power Unit. (The lack of an APU is a critical failing of the Challenger-2, which must run its main engine to power any of its systems, burning fuel while sitting still.)--Stephen V Cole