Turbochargers increase the horsepower of an engine by boosting the intake a= ir pressure. I have no idea if a turbocharger makes an engine more efficie= nt or simply more powerful. Does anyone attempt to recover waste heat from a gasoline or diesel engine = used on a vehicle ? ( Yes, I am sure someone will mention the heater that warms the vehicle's i= nterior ) gus in denver 99gus --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .