THOUGHT about shock absorbers recently? Thought not. Maybe you should... All motorists know that driving on wet, windy, icy or snowy winter roads can be hazardous, and most sensible drivers take extra care when doing so. However, few realise that the effectiveness of taking precautions such as reducing their speed, fitting winter tyres for extreme weather conditions, or even driving a car equipped with the latest safety technology such as antilock brakes (ABS) or an anti-skid system (ASR), can be seriously compromised if their vehicle has worn shock absorbers.

Shock absorbers help keep the car's wheels in contact with the road – which is important for good braking and steering at the best of times, and particularly vital in winter conditions.

However, shocks wear out gradually and become increasingly dangerous as they do so, but few drivers notice the symptoms, making it particularly important that they have their vehicle's shocks checked professionally every 20,000 kilometres, particularly as winter approaches.

Independent research carried out by testing organisation GTS in France has given a graphic demonstration of how worn shock absorbers can render ABS and ASR systems significantly less effective.

In a braking test on icy roads in the French Alps, a Mercedes-Benz C250 Estate fitted with ABS and 50 per cent worn shocks took 1.8 metres longer to stop from 35km/h than it did when fitted with 100 per cent efficient shock absorbers.

A second test showed that 50 per cent worn shocks also affected the car's anti-skid system. With 100 per cent efficient shock absorbers, the car had greater traction control, with a period of lost traction 37 per cent less than that experienced with 50 per cent worn shocks. And even in the winter test conditions, the Mercedes was able to accelerate 16 per cent faster with the efficient shock absorbers compared to the worn ones.

A Peugeot 206 with ABS and 50 per cent worn shocks took an additional 1.2 metres to stop in the same GTS braking test, compared to its stopping distance with new shocks.

Worn shock absorbers also cause aquaplaning to occur at lower speeds, give the driver less control when cornering or caught in a cross wind, increase wear on tyres and other suspension components, cause uneven/oscillating headlight level which can dazzle on-coming drivers, and increase driver tiredness and reduce their response times.

Fernando Monton, Group Ride Control Product Manager of shock absorber specialists Tenneco Automotive said: "The greater stopping distances, longer periods of traction loss and slower acceleration times demonstrated in the GTS tests could certainly contribute to a driver being unable to avoid an accident or increase the severity of an accident.

"Driving in ice, snow or fog in winter is always potentially dangerous, and reducing speed, fitting winter tyres and even having sophisticated safety technology simply isn't enough if a vehicle's shock absorbers aren't working efficiently.

"Having a car's shocks checked before winter sets in, and replacing them as necessary with new shock absorbers can make a significant difference to winter driving safety," he concluded.