CSF Racing Auxiliary Radiator - Mercedes AMG W205Mercedes AMG GT GT 53 GT 63 S W205 C63 W166 GLE63 Auxiliary Radiator The High Performance All Aluminium Auxiliary Radiators work in conjunction with the rest of the cooling system to reduce temperatures throughout. This is critical as the Auxiliary Radiators not only help keep engine water temperatures lower, but also are utilized as the heat exchange medium in the air to water charge air coolers for the turbocharger system to reduce intake air