A system for cooling charge air from a turbo- or supercharger and exhaust gas recirculated from an exhaust gas recirculation valve in an internal combustion engine. The system includes a radiator and parallel charge air and exhaust gas heat exchanger units, the charge air heat exchanger unit having aluminum tubes and fins for air cooling the charge air, and the exhaust gas heat exchanger unit having stainless steel tubes and fins. The charge air heat exchanger and the exhaust gas heat exchanger units are each disposed adjacent the radiator, on the same or opposite sides. Alternatively, there is provided a pair of combined charge air cooler and exhaust gas cooler heat exchanger units, with a first heat exchanger unit having stainless steel tubes and fins, and a second heat exchanger unit having aluminum tubes and fins. The heat exchanger units are disposed on opposites sides of the radiator.