Citroen

Menu

Value my car Find us Call us My account

Important Questions Answered About Diesel Cars

21 March 2018

Diesel cars get a lot of negative coverage, demonised by many in the national media and government. Not so long ago they were the preferred option, with financial incentives for buying a diesel car, but now they are the hardest hit by taxes with the first year road tax (VED) rising by one band from April 2018.  

With all the bad press it can seem amazing that anyone buys or drives a diesel, but there are still many being produced (even if sales are falling). In order to understand more about the safety, advantages and disadvantages of diesel cars, we answer some of the important questions.

What’s Bad About Diesel?

Compare similar models of a petrol and diesel car and you may think the diesel is the better choice. Most produce fewer CO² emissions and deliver a better fuel economy (mpg) by 20% on average. For this reason, the UK government encouraged drivers to switch to diesel by offering lower road and company car tax.

However, further research and examination has revealed that diesel engines produce much higher levels of nitrogen oxides (NOx). These are one cause of air pollution, which impact upon human respiration and exposure can lead to premature death. The UK is looking to clean up its air to meet national and European targets and prevent such health issues, which is why diesel cars are being discouraged.

Are There Good Diesel Cars?

Some diesel cars are less polluting than others. Older models are by far the worst, as since 1992 the EU has been tightening up on emissions with its own set of standards. These are applicable to all new cars registered from January 1993 onwards when the limit was 0.97g/km of NOx.

This has improved to the Euro 6 regulations requiring new diesel cars produced from September 2015 to have a maximum limit of 0.08g/km of NOx emissions. Therefore, newer diesel cars are a far better option.

Does BlueHDi Offer a Solution?

The latest generation of diesel engines from Peugeot use BlueHDi technology, complying with Euro 6 regulations while delivering excellent fuel economy and low CO² emissions as well. Using an innovative location for the Selective Catalytic Reduction (SCR) it reduces NOx production by up to 90%.

In some cases, NOx emissions are lower than in Peugeot’s petrol PureTech engines. For it to be effective the AdBlue levels need to be topped up around every 12,500 miles. Diesel cars with a BlueHDi engine offer a much safer, cleaner and efficient option.

What Should I Look for When Buying a Diesel?

When looking to buy a diesel car, most of the same factors should be looked at but with a greater focus on certain ones:

  • Age: Older diesel cars are often the worst for emissions and can incur higher tax costs even if their price is low.
  • Euro Rating: Look for ones that comply with Euro 6 if possible, or at least Euro 5 as these are exempt from the likes of London’s T-charge.
  • Fuel economy: Check that fuel economy is still decent and better than a petrol equivalent.  
  • NOx emissions: If you can’t see the Euro rating then check what the NOx emissions are, the lower the better.
  • CO² levels: These still impact on tax costs so are important to check.

Which are the Most Efficient Diesel Cars?

The New Peugeot 3008 SUV was named ‘Car of the Year’ in the Diesel Car Top 50, thanks to its BlueHDi engine. The same was true when the Peugeot 308 Active won European Car of the Year in 2014, as it was the most efficient diesel car in the C-segment. Essentially, any car using the BlueHDi engine technology will be highly efficient with low emissions levels, mostly produced in the last few years.

Not all diesel cars are the air polluting killers the media makes them out to be. There are plenty of new diesel cars with low NOx emissions and a good fuel economy for sale. Just ensure you research thoroughly to avoid any of the worst models.

Cookies

We use cookies to make sure you get the best experience on our website. If you continue without changing your settings, you're agreeing to receive all cookies on the Stellantis &You UK website.