Over the last 15 years or so there has been an extraordinary rise in the usage of diesel. Manufacturers like BMW have not only adopted diesel but now are among the leaders of in diesel engine technology.
This has been partly down to the advances in engine refinement but as a way for motorists to offset the ever spiraling costs of fuel.We all know the virtues of diesel when it comes to fuel consumption.
Over the last 15 to 20 years, common rail diesel engines have increased economy, improved refinement, reduced emmissions while the performance has moved to a whole new level.
But have people become blinded by the all seducing figures of miles to the gallon/litre and blinkered to the other figures and costs that should be taken into account when choosing your next car.
Diesel engines are more expensive to service, often with shorter servicing intervals and all the time the cost of purchasing diesel has not just closed the gap on petrol in price but overtaken and marched ahead of petrol.
Diesels only work at their most efficient when they are used for long distances and frequently. There has been an expendential rise in the numbers of diesel family vehicles. Are these vehicles covering the sort of mileages that make diesel the optimum fuel choice?
Which? consumer magazine has conducted extensive research into the subject and has concluded that despite the lower tax brackets afforded to most diesel over their petrol equivalent – diesels are still dearer to run for the average motoirist.
Which? took a number of models and compared the fuel costs over the average mileage (based on their readers survey last year) of 10,672 miles. Unsurprisingly, in terms of fuel costs the diesel powered cars worked out to be cheaper. However, diesel models carried a price premium of £1000 to £2000 over the petrol models that would take on average of 14 years motoring to recoup by fuel economy savings alone.
Technological advances in petrol engines have also seen improved efficiency that are closing the gap on diesel. This does not include the fact that petrol is around 5.5p per litre cheaper than diesel.
Which? Magazine Managing Director, Richard Lloyd, commented, “Diesel cars are known for the efficiency, but with higher pump prices and the price premium for diesel, it may make more sense for families to opt for petrol”.
Gordon Murray, legendary Formula One car designer is opting for petrol power with his new city car, the T25, Murray stated in a recentinterview that manufacturers should remain “agnostic” about the fuel choice for future designs.
Which? also concluded that people should not put their faith in the fuel economy testing figures quoted by both the manufacturers and EU as they tended to fall short of the real world figures. This was true for both petrol and diesel test results.
Another factor that was brought to light during the research was that in the first three years of life petrols were more reliable than their diesel counterparts. The gap in reliability only increased in the favour of petrol as the cars got older. Often the premium prices for diesel also includes the price of replacement parts over the petrol equivalents too.
Models from all market segments were included in the test from superminis up to 4 x 4 but in the case of superminis the Ford Fiesta was used, the test results were: The Ford Fiesta 1.6 diesel costs £15,495 and returns 62.8mpg, compared to the Fiesta 1.25 petrol model that costs £13,095 and returns 47.1mpg. If the driver was to cover the average mileage of 10672 miles it would take owner 7.8 years to recoup the cost.
If you look further up the range at the BMW 530d which weighs in at £40,945 and returns 40.9mpg to recoup the additional cost over the petrol equvalent that costs £37,300 and does 34mpg would take 14.1 years.
This research arrives when, for the first time, diesel new car registrations outstrip those of petrol and alternative fuels.