Should I buy a diesel car?
It’s a question we get asked a lot at Autotrader. With the recent demonisation of diesel in the press, #dieselgate, and increasing concern about the environment, it’s no wonder people are confused about whether they should still buy a diesel car. Here’s everything you might want to know.

Well, the government promoted diesel for more than ten years, as diesel cars have better fuel economy, and lower CO2 emissions than their petrol equivalents. There was a big focus on cutting CO2 emissions, and diesel cars were seen as a way to do this. Consequently, diesel car buyers were rewarded with lower road and company car tax. However, in the past couple of years, several things have happened that have turned the world against diesel. First, there was the Volkswagen #dieselgate scandal, when emissions tests were rigged by the company. Cars’ emissions and fuel economy figures were much worse in everyday use. The government also needed to start tackling the high levels of pollution in cities. It is repeatedly breaking air pollution limits and getting sued by the European Commission. Diesel engines produce nitrogen oxides (NOx), which contribute to pollution. There are more nitrogen oxides produced by older diesel cars and other vehicles, so the government announced there would be higher charges for people driving the most polluting diesel engines in urban areas at peak times. Then, in November 2017, Philip Hammond’s confusing Budget statement suggested the cleanest new diesels would be hit hardest with a sales tax in the future. Which, understandably, put even more people off buying them.
As diesel has gone through a bit of a crisis of late, there are some really good discounts available on diesel cars too. So much so, that it will likely offset any further taxes that might be planned in the coming years. Diesel cars do tend to cost more than petrol equivalents, cost a bit more to service, and the fuel costs more. But if you are doing a lot of miles, you’ll hit the ‘break-even’ point, where the costs cancel each other out. It is important to do the maths though, and work out if the additional cost will be worth it for you. On top of that, petrol and diesel cars do feel different to drive. Diesel cars have a strong pull from low down in the rev range, so they’re more relaxing to drive. Because of the strong pull, diesel also helps if you regularly carry lots of passengers or cargo, or tow a caravan.

However, older diesel cars have much higher particulate and CO2 emissions than newer cars. The levels allowed have been increasingly tightened by the European Union since 1992. New cars sold currently have to meet Euro 6 emissions standards, which means 99% of all soot particles are removed from the exhaust. The cars have to be fitted with DPFs, most newer diesels have AdBlue tanks (find out more about AdBlue), and have various systems which convert NOx into nitrogen and water.

For the first year of tax, the amount is calculated differently to consequent years, and it’s based on the car’s CO2 emissions. From 1 April 2018, diesel cars which do not meet new emissions standards have moved up one car tax band. The government wasn’t raising as much money in road tax as it could under the previous system, as cars that emitted less than 99g/km CO2 used to qualify for free road tax, but don't any more.

ULEZ is in addition to the Congestion Charge, which is an £11.50 daily charge for driving a vehicle within the charging zone between 07:00 and 18:00, Monday to Friday. Find out whether or not you need to pay the Congestion Charge. It's also likely other cities around the UK will introduce similar ULEZ schemes in the coming years.

Alternatively fuelled vehicle searches currently stand at 4% – a figure which has only gone up 2 percentage points in the past two years. The fall in diesel searches is due to confusion and a lack of clarity on the situation. But also, as well as moving away from diesel, consumers are still sticking with a fuel type they know and understand – petrol. This is possibly why average CO2 emissions from cars are set to rise for the first time in two decades, according to figures from the Society of Motor Manufacturers and Traders (SMMT). Diesel engines emit on average 20% less CO2 than their petrol counterparts.
