Today's off-road equipment designers are searching for ways to reduce manufacturing and warranty costs through better performance of critical component parts. High-performance polyimide parts are being used in demanding applications as replacements for metals and other materials in transmissions, drive trains, and hydraulic systems. The polyimides' inherent properties of self-lubrication, flexibility, compliance, and wear rates give them advantages over metals. The high load bearing, high PV, high temperature resistance, and low creep properties place them above the engineering plastics.This paper describes application and design concepts to illustrate where high-performance polyimide components can contribute to cost effective performance improvements in off-road equipment. Physical properties important to engineering design, such as strength, creep resistance, thermal expansion, wear life (in both lubricated and dry systems), and frictional characteristics are highlighted.