Petrol or diesel: which should you buy? - Total ownership costs: diesel wins

Of course, there's more to car ownership costs than the fuel outlay, and diesel cars will reward their owner in other areas.

After factoring in residual values, insurance costs and servicing costs, many diesels offer marked savings over three years of ownership.

Diesels also trump petrols on depreciation - the used car market is prepared to pay higher prices for well-maintained diesels, even if they have high mileage.

We found that diesels are also usually cheaper to service and insure.