An improved TEG for the Heavy Duty Class Eight Diesel Trucks is under development at Hi-Z Technology. Previous efforts were focused on TEG prototype development, fabrication and testing. The prototype was able to generate about 1kW of electrical power from the Cummins NTC 350 Diesel engine exhaust but exhibited mechanical degradation during the subsequent road test due to module movement. The current TEG is designed to be equipped with the improved HZ-14 Thermoelectric (TE) modules, which features better mechanical properties; also, the modules are securely held in place.