Noting that it might seem like a contradiction, The Car Connection (TCC) website said one of the world's leading HVAC suppliers is betting that the greenhouse gas, carbon dioxide, can actually help improve the environment. According to TCC, Behr is pitching a new air conditioning system that replaces the refrigerant, R134a, with CO2. The head of the German supplier's technical centre, Thomas Heckenberger, told TCC that, on a typical European car, older A/C systems use 0.62 litres of fuel for every 100 kilometres they are driven and even today's more efficient designs still require 0.53 l/100 kmh - a comparable CO2 air conditioner would lower consumption to 0.47 litres.