Should I buy a diesel car?

Why diesel cars are becoming less popular?  

If you’ve been car shopping recently, a diesel might not be at the top of your list. You’re not alone; diesel cars have fallen out of favour in recent years for many different reasons. Despite offering great fuel economy and producing lower CO2 emissions than other fuel types, diesels are increasingly being referred to as high polluting vehicles. Their contribution to pollution levels, especially when travelling at low speeds, has led to diesel car owners facing higher rates of tax and paying higher charged to enter Clean Air Zones.  

These costs have added to the controversy that occurred in 2015 when several diesel manufacturers were found to have tried to subvert emissions tests in a scandal that came to be known as Dieselgate. As a result, the residual value of these vehicles is falling and new and used car buyers are much more cautious when it comes to buying a diesel car.  

Diesel cars and the environment 

When they first hit the market, diesel cars were promoted as an environmentally friendly alternative to petrol vehicles. Diesel engines do produce lower CO2 emissions, but they also emit nitrogen oxides, one of the biggest contributors to the air pollution that causes an estimated 7m deaths per year according to the World Health Organisation.  

Diesel engines also product particulate matter, which studies have shown can damage the lungs and other organs. It’s for this reason that, despite their positive CO2 emissions, diesels are increasingly either being banned or charged large amounts to enter highly populated inner-city areas. ULEZ charges for diesel cars are currently in operation in London, Bristol, Bradford, Bath, Birmingham, Tyneside, and Portsmouth with more planned across the UK.  

Advantages of diesel cars 

Despite becoming less popular in recent years, there are still several advantages to owning and driving a diesel car:   

• Fuel economy  

If you’re someone who travels a lot of long distances and spends most days on the motorway, a diesel car could offer better fuel economy than its petrol alternatives. Tests have shown that diesel engines could be up to 20% more efficient than petrol and can be especially good value for those who have an average mileage of over 15,000 miles a year.  

• Pulling power  

Whether you regularly need to tow a caravan or want to buy a large car with space for all the family, a diesel could be your best option. As diesel engines have lower revs, they tend to offer more torque, which makes it easier for them to power heavy vehicles like MPVs and SUVs or if you have something to tow.  

• Cleaner engines  

Car manufacturers have seen the problems caused by diesel engines’ nitrogen oxide emissions and particulate matter and have taken to steps to address them with newer models. In fact, the latest diesel cars are comparatively clean thanks to the addition of particulate filters and a urea-based chemical that’s now included in the exhaust system.  

• Cheaper used prices  

The controversies and uncertainty surrounding diesels have made them less desirable on the used car market, which means there could be some great bargains available. You might be able to find a diesel version of your dream car available at a cheaper price, which could offset higher tax and any emissions charges.  

Disadvantages of diesel cars

Depending on your circumstances, a diesel car might not be the right choice for you. Here are a few of the disadvantages to keep in mind:  

• Clogged engines  

While diesel cars often perform well on the motorway, they aren’t as efficient on short journeys. If you’re someone who mainly drives in the city and ends up in stop-start traffic, you might want to avoid diesels. It’s all down to the diesel particulate filter (DPF), which is designed to combat particulate deposits. Unfortunately, only sustained high-speed journeys will generate the high temperatures needed to burn off the particulate deposits caught in the filter and stop it from getting clogged. If you don’t regularly hit high speeds and the filter does get clogged, you could end up with mechanical complications and hefty repair bills.  

• ULEZ charges  

Another drawback for city drivers is that you will have to pay a high fee to enter a ULEZ area in a diesel car. In some cases, diesels are banned completely. The daily ULEZ charge for diesels in London is £12.50 a day and as more cities introduce clean air zones, the cost of driving a diesel in a city will get even higher.  

• Higher maintenance costs  

If you do manage to bag a bargain and pick up a used diesel car, you might find that your running costs are higher than they would be with other types of engines. Diesel fuel can be more expensive at the pump and servicing fees are also higher.  

• Higher purchase price  

Used diesel cars may be cheaper to buy, but brand-new models can be a lot pricier than their petrol equivalents. This is due to new diesel cars needing a stronger engine and to be fitted with diesel particulate filters to run smoothly and reduce harmful emissions. 

The future of diesel cars in the UK  

Does this mean that diesel cars will become extinct in the UK? There’s certainly been a shift away from diesel engines and sales of both new petrol and diesel cars will be banned from 2030. However, used diesel cars will be bought and sold after the 2030 ban and, while older and dirtier diesel engines may be banned completely, modern models that are cleaner and don’t exceed emissions limits could remain on the road. Even so, some manufacturers are moving away from diesel engines with Porsche, Suzuki, and Toyota all announcing that they plan to slow down or stop manufacturing diesel vehicles completely. 

Should I sell my diesel car?

With all this in mind, should you try to sell your diesel car now? There’s no right or wrong answer, the best choice for you will depend on your individual circumstances. When the ban on new diesel car sales comes into force in 2030, it won’t prevent diesel cars being bought and sold on the used car market so there’s no need to panic and get rid of your car immediately. However, prices are falling and it’s unlikely that they will pick back up in the future. If you live in a city or own an older diesel car, you might want to consider your options and act sooner rather than later. There are generous scrappage schemes available and some local authorities are also offering financial incentives to encourage diesel drivers to swap to a different type of car.  

Should I switch to an electric or hybrid car?  

There are advantages and disadvantages to switching from a diesel to an electric or hybrid car:  

• They may be more expensive to buy but they are cheaper to run and maintain than diesel cars 
   
• They produce little or no emissions so are ideal for city drivers or those who live in ULEZ areas  
   
• The electric vehicle charging infrastructure in the UK is still relatively limited so could cause problems if you use your diesel car to travel long distances on the motorway. In this case, a hybrid might be a better fit for you.  
   
• The used car EV market is quite small, but you could find it easier to resell in the future.