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17 Apr 2018
Jamie Gibbs Alice Campion

Could a diesel car work for you?


Diesel cars have decreased in popularity recently with new taxes being introduced. But could they be a better option for some motorists? diesel

Diesel was originally introduced as an alternative fuel source to petrol as the levels of CO2 were much lower. It was later discovered that diesel emits NOx, a harmful gas that can cause serious health and respiratory problems. 

It was announced last year that from April 2018, tax for diesel cars that don’t comply with Euro 6 emissions standards will increase. 

Since then the enthusiasm for diesel has rapidly decreased. But for some motorists diesel is the best option.  

The fuel economy for a high annual mileage is often better for diesels than petrol or alternatively fuelled vehicles. 

So behind the headlines, is diesel really that bad? We take a look at whether diesel could be the most cost effective option for you. 

READ MORE: Fuel Barometer 

Euro 6

From April the 1st 2018, if you’re buying a diesel car that doesn't meet Euro 6 emissions standards you will face a higher rate of tax.

Euro 6 is a European Union directive that aims to reduce the levels of Nitrogen oxide, Carbon Monoxide, hydrocarbons and particulate matter. 

For diesels, last year the permitted level of NOx was 180 mg/km. This has now dropped to 80 mg/km to reduce these pollutants. By doing this the levels of these harmful pollutants will be reduced, lower CO2 emissions and improve fuel economy. 

However, these changes won't affect you if your car is already registered, and the tax you pay won't change for the rest of the car’s life. 

READ MORE: Driving law 2018: What to expect this year


When can diesel work for me? 

Diesels have not been in public favour recently. However, in reality there are some scenarios when diesel can be the most cost-effective and economical option. 

A lot depends on the diesel particulate filter (DPF). The DPF traps and stores diesel particulate matter or soot from the exhaust gas of the diesel car. 

These have a certain capacity and when it’s met, the filter has to be emptied or burned off, this regenerates the DPF. This process reduces the harmful NOx emissions that diesels are known for. 

The DPF can become clogged if you make frequent short journeys. And replacing a diesel particulate filter can be an expensive venture. This is why diesel is not recommended for city travelling. But if you’re doing long stints on the motorway, the DPF is less likely to get clogged up.

If you have a high annual mileage, diesel is most likely the best option. At the moment, the fuel economy of diesel unfortunately can’t yet be matched by petrol vehicles.  

READ MORE: UK car tax bands explained


Should I buy a diesel car? 

The price of diesel cars has decreased considerably since the tax changes have come into force. 

But new diesels sold from 2015 onwards are the cleanest they have ever been. With the most recent having newly developed specifications that are designed to target the pollutants of diesel cars.

READ MORE: How to tax your car

Scrappage schemes

If you have an old diesel now, and are concerned about the emissions, many dealers are launching scrappage schemes

Cars eligible for these must have been registered before the 31st of December 2009 and have been owned for over six months. Some dealers are offering up to £6,000 towards a new more economical vehicle.

READ MORE: Scrappage schemes 


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