The introduction of new refrigerants for mobile air conditioning, in particular the change to CO2 (R-744) with its highly challenging technical operating conditions, asks for new aluminium solutions. The condenser which is used in current air conditioning systems based on R-134a will be replaced by a CO2 (R-744) gas cooler. Multi Port Extruded aluminium for CO2 heat exchanger applications are developed to resist the high pressure of the CO2 system.