This paper describes the VIPER II, the Vehicle Inertia Parameter Evaluation Rig, developed by SEA, Ltd at the request of the US Army’s Tank Automotive Research, Development and Engineering Center (TARDEC). The previous machine was the VIPER I, built in 2000. The new machine is built to measure vehicle center-of-gravity height, the pitch, roll, and yaw moments of inertia, and the roll/yaw cross product of inertia. It is made to test nearly all of the Army’s wheeled vehicles, covering a range of weights from 3000 to 100,000 lbs, up to 150 inches in width and up to 600 inches in length. Commercial vehicles could also be tested. The machine was installed in March, 2014 in the TARDEC facility in Warren, MI. The paper describes the need for such measurements, the basic features of the machine, the test procedure, and the results of early testing. The design specification for accuracy was 3% for all measurements, but the actual VIPER II accuracy is usually better than 1%.