The US Army is moving ahead with the joint light tactical vehicle (JLTV), with prototypes expected to be ready by May 2010.
The JLTV is expected to provide more blast protection and mobility than the Humvee in a package light enough to be hauled by a helicopter.
The Pentagon has called it the centrepiece of the military's long-term lightweight vehicle needs, with ten planned variants in three weight classes.
The vehicle needs to be light enough to be carried by the army's CH-47 Chinook and the marine corps' CH-53E Super Stallion.
The curb weight (no armour or payload) is required to be less than 12,000lb for the lightweight 'A' class and less than 16,600lb for the 'B' and 'C' weight classes.
The CH-47F is capable of hauling a JLTV of up to 17,940lb, while the CH-53E is capable of lifting up to 16,800lb externally.
According to a JLTV spokesman David Branham, the vehicles may exceed 20,000lb when payload and armour are added, and officials will test tradeoffs to the 'B' and 'C' variants to bring those vehicles under 20,000lb.
The finalists for the project are BAE Systems / Navistar, Lockheed Martin and General Tactical Vehicles. The contract was awarded to these finalists in October 2008.