FLEET managers are being urged not to delete sunroofs from options lists in cars fitted with air conditioning following a study which claims the combination of the two improves driver safety.

Separate research teams at global flow circulation specialist IVM Technical Consultants and at Stuttgart's Sienna University commissioned by sunroof manufacturer WebastoHollandia have concluded that most air conditioning systems need extra help to provide the optimum interior climate to maintain alertness.

Hugh McTernan, Webasto Sunroofs' UK general manager, said: 'The studies show that a vehicle's cabin air circulation, air exchange and temperature control are all significantly improved when the two work together.'

A medical study by the Stuttgart team showed that tilting or opening a sunroof had a positive effect by increasing alertness, maintaining and regenerating blood oxygen levels, reducing elevated blood levels of carbon dioxide and carbon monoxide, helping to balance humidity and reducing the negative effects of smoking more quickly.