By using air-conditioning the fuel consumption of any vehicle increases by 10 to 15 percent. The additional consumption depends on various factors: length of the trip, vehicle age, ambient temperature, solar radiation, motorisation and preferred inside temperature.
The systems engineering is particularly important: being equipped with a simple, non-regulated air-conditioner the vehicle consumes up to 2.5 times of the fuel amount a vehicle with a modern, electronically controlled system consumes.
No information for car users so far
Currently, there is no consistent measurement method that provides information on the additional fuel consumption caused by air-conditioning systems. The official consumption data provided by manufacturers is determined by the so-called New European Driving Cycle (NEDC). However, additional sets such as air-conditioning system or heater are not considered in this standardised consumption test. Thus, car buyers so far do not have any indication to the actual efficiency of the air-conditioning system in the car.