Has diesel come to the end of the road?

According to magazine, buyers are showing a massive swing away from diesel cars, back to petrol models. In 2014 and 2015, diesel cars accounted for 50.1 and 48.5 per cent respectively of new-car sales but now the market has gone the other way and more than 70 per cent are favouring petrol. So if you are buying a new car, which way should you go?

This sudden change of opinion has been driven by the Government, which vigorously promoted diesel for its better efficiency and reduced CO² output but now blames diesels for high emissions of nitrous oxides. This has developed into a scare story, making buyers think that diesels would face punitive taxes. Then there was all the bad publicity over the Volkswagen emissions scandal, revealing its diesel cars had been tweaked to defeat emission tests and give favourable readings.

Petrol cars are now much more efficient, too. In the days when a petrol car gave you 25mpg and a diesel raised it to 40mpg, you really felt the benefit. Today most new cars will take you at least 40 miles on 4.5 litres (one gallon) of petrol. If the equivalent diesel does 50 miles, that does not seem such a big deal.

Annual tax based on CO² emissions remains an important factor, with the rate increasing from £30 a year to £95 if CO² output exceeds 120g/km, rising to £460 for high polluters emitting over 255g/km.

The diesel engine will invariably be in at least one bracket lower than the equivalent petrol model but, with a new chancellor at the helm and talk of the new anti-diesel policy, the rates may change in a future budget with adverse effect on resale values.

Fuel cost used to be a factor, with diesel costing a lot more than petrol, but the AA’s latest fuel report shows the UK’s average fuel costs to be the same for both petrol and diesel — £1.12 at fuel stations and £1.09 at supermarkets. In France, petrol is more expensive than diesel, costing £1.08 equivalent, against £1.02 for derv.

It is not all about money, though. The diesel car goes much further without refuelling and its engine generally needs fewer routine services, other than oil and filter changes, which must not be neglected. It is also less prone to starting problems in cold, damp weather. It gives higher torque at lower engine revs and is generally higher-geared, giving more relaxed cruising.

Against these benefits, the petrol car is cleaner to refuel — no need for a plastic glove to protect your hands from the long-lasting smell of diesel. Its engine is much freer-revving, needing fewer gear changes and, although diesel cars have become much less noisy, the petrol engine is still much quieter.

Last year, I joined the swing away from diesel, buying an Audi A3 Cabriolet with 1.4-litre turbocharged petrol engine, which comfortably exceeds 45 mpg. Unless your annual mileage will exceed 7,000 a year, making the cost saving worthwhile, I recommend you go for petrol. The cost difference is no longer a big factor in choosing between fuels