Motorists could be spending up to six times more than they have to on spare car parts according to new research from independent warranty provider, Warranty Direct.

Researchers compared the cost of new parts on a selection of four-year-old vehicles from the UK’s top 10 selling manufacturers, with prices gathered from franchised dealers, independent garages and high street motor accessory retailers on six common parts: starter motor, air-con compressor, wheel bearing, alternator, shock absorber and radiator.

They found that motorists could save over £395 (169%) on an air-con compressor for a Mercedes E-Class if bought over the counter instead of at a franchised dealer. In another case, a replacement wheel bearing for a Honda CRV cost 517 percent more from the dealer than the £21.88 charge from a motor accessory retailer.

The service and repair industry is worth over £10 billion annually.

The four-year-old cars analysed by Warranty Direct engineers would no longer be covered by the manufacturer’s traditional three-year aftersales warranty.

"For anyone who has owned a car from new, this is the point when you really start paying for everything that goes wrong, and realise that it pays hugely to shop around," says Duncan McClure Fisher, of Warranty Direct.

Motor accessory retailers proved to be the cheapest source for more than 8 out of 10 parts with an average saving of 65%. Franchised dealers and independent garages were equally cheapest in 9% of cases respectively.

However, the gap between the cheapest and most expensive source was more than double for nearly half of the parts compared.

McClure Fisher says: "Although there are still some dramatic disparities, some franchised dealers have started to recognise the need to slash prices on older vehicles in order to retain custom so it’s worth trying to haggle with them."

For example, franchised VW dealers were cheaper than independent garages on 5 out of the 6 parts analysed, yet Mercedes could only compete on one.

Sample prices disparities