Western Star Truck Sales Inc. announced its new Extreme Duty (XD) off-road package and the launch of the MBT-40 Transformer chassis. The Western Star XD off-road package is engineered specifically for extremely rugged environments, the company said, and is available on both the 4900 and 6900 models. Western Star plans to open the XD off-road package up to other models in the future. The 6900XD off-road MBT-40, dubbed the Multi-Body Transformer for its ability to quickly change from one fully functional in cab controlled body application to another, is the first XD off-road series offering from Western Star.