It used to be a straight forward comparison. Diesel cars were more economical and had a cheaper tax rating than petrol vehicles. But petrol was cleaner and gave a better performance.

However, things have changed. Does that now mean the choice between buying a diesel-powered motor or a petrol one is a whole different story?

Diesels – the big, bad wolf?
Diesel engines have been developed by manufacturers to not only have pulling power but also to have an often turbo-charged performance. Add to that zero or low annual vehicle tax rates and the diesel was very attractive.

But, with the new tax rates on cars registered after April 2017, only in the first year will diesel cars attract a lower tax rate. After that it is the standard rate of £140 per year.

Before the excise licence changes, although diesels were more expensive than petrol powered cars in the showroom, running them would work out to be cheaper and you could recoup that extra cost often within a few years. That will now take longer and the savings will be smaller.

Is petrol the prince among engines?
Overall, a petrol-powered car performs better, smoother and quicker in acceleration, especially compared to a non-turbo diesel. Even though a petrol car will rev higher, they are generally quieter. They are also lighter without the heavy diesel engine and usually handle better.

With all the changes, the Volkswagen emissions scandal and the general negative press on diesel’s environmental impact, the residual value of diesels isn’t holding up. In other words, when you come to sell, you will get less for it.

Is it all over for diesel?
If you are a high mileage motorist, say completing more than a 1,000 miles a month, then a diesel is more likely a better bet.

This would particularly apply if you’re doing motorway rather than in town trips. Longer journeys heat up the engine, so that the Diesel Particulate Filter, or DPF, which catches the tiny soot-like particles before they leave the exhaust, works to full capacity.