CSF Front Mount Heat Exchanger w/Rock Guard 2015+ Mercedes Benz C63 AMG (W205)Integral to the new 4. 0 liter Twin Turbo engine's power output is not only the turbochargers but the charge air (compressed air) cooling system. A system to cool the charge air is required because when the turbochargers compress air, it heats up. For optimum performance, this air needs to be cooled again. Cooler air going into the engine means much denser oxygenation and improved knock resistance, two key factors when seeking to maintain or improve