THE AA has called on car makers to provide full, independently warranted information on the fuel costs of non-essential equipment like air conditioning. The call follows research by the motoring organisation which has revealed that fleets are paying a hefty fuel premium for keeping their drivers cool on the roads.

According to the AA, air conditioning can reduce a car's fuel consumption by as much as 15%, at a cost of between 3.5p and 7p a litre. David Lang, the AA's chief engineer, said: 'Motor manufacturers now promote air conditioning as one of the musts for new car buyers, though none of them talk about the hidden costs. As the motorist is hit more and more by fuel tax, motor manufacturers and car accessory companies should provide full information, verified by independent testing, on the fuel costs of non-essential equipment.'

The AA research found that in suburban driving conditions when the ambient temperature is 24 degrees, consumption rose by 11% for a 1.3-litre supermini, by 10% for a high performance 1.8 upper medium petrol saloon, and by 9.4% for a 1.9 TDI upper medium car. At 70mph, with an ambient temperature of 17deg C, the 1.8-litre saloon suffered a 4.2% increase in fuel consumption.