The last few years have not been kind to diesel engines. Once lauded and incentivised as a way to reduce carbon dioxide emissions, and thereby help heal the hole in the ozone layer, they are now motor non grata because of the other harmful pollutant they can pump out of the exhaust, namely nitrogen oxides and particulate matter, which are proven to be damaging to our lungs and other organs.
Their pariah status really began in 2015, when it became clear that some car manufacturers were using cheat devices to subvert emissions tests — a scandal known as Dieselgate, in which the Volkswagen Group was the most notable culprit. What it meant was that diesel vehicles weren’t as clean in the real world as consumers and governments had been led to believe, and so a political clampdown on the fuel became turbocharged.
First came an increase in the first-year vehicle excise duty payable on diesel cars, alongside a rise in the company car tax rate.
Then came further disincentives; in recent years we’ve seen the establishment of low-emissions zones in towns and cities, which charge daily fees to drivers of older diesel vehicles, while the government’s announcement of a ban on the sale of new petrol and diesel cars by 2030 has also contributed to an enormous decline in diesel car sales.
In 2012, diesel cars outsold petrol but in 2021, just 135,773 diesels were registered, compared with 762,103 petrols. Sales of diesel plummeted 48.1% last year alone.
Diesel car sales are now eclipsed by those of hybrid and pure-electric vehicles, even.
This has prompted questions from a lot of diesel owners as to whether they should abandon their cars in favour of hybrid or electric models and, even if they do so, will their old car be worth anything in a rapidly changing marketplace?
Thankfully for fans of the oil burner, although diesel may be in the autumn of its years, it does still have a few things in its favour.
Why you might still want to buy a diesel car
The main thing that diesel has going for it is the reason it was so highly praised in the first place — its relatively high fuel economy compared with petrol, and lower CO2 emissions, particularly over long distances.
If a driver covers a lot of motorway miles every year, a diesel may make more financial sense despite a higher initial cost and higher prices per litre at the pumps.
For a large, heavy vehicle such as an MPV or SUV, the greater torque (twisting force) of diesel fuel makes it more suitable than petrol, and ideal for towing or off-roading.
Though rural drivers may not be unduly affected by low-emissions zones in urban areas, the latest diesel models (i.e. those that are Euro 6 emissions regulations compliant) are generally exempt from the city-centre bans and charges that affect older, more highly-polluting diesels. At present, anyway.
What’s more, the latest diesels can be quite clean. By adding an urea-based chemical (usually referred to as “AdBlue“) into the exhaust system, the harmful emissions can be near-neutralised.
The trouble is, even this system isn’t enough to stem the tide, and diesel’s reputation is shot.
Reasons not to buy a diesel
If you live in or frequently drive in an urban or suburban area and most of your journeys are short, there’s not much cause for you to buy a diesel — you’d be better off going with a petrol, hybrid or electric model instead, as the fuel savings won’t offset the higher purchase price of a diesel car, and diesels aren’t at their most efficient in stop-start traffic conditions.
Frequent short journeys may also clog the car’s diesel particulate filter (DPF), one of the things that helps prevent some of those nasty pollutants entering the air. Only a sustained, high-speed run (such as a motorway trip), will generate the temperatures required to burn off the most harmful pollutants, and not doing so regularly risks clogging the filter to a point where mechanical complications and hefty repair bills can ensue.
Even with clean air zones in cities currently exempting newer (Euro 6-compliant) vehicles, that could change in the future as emissions rules become tighter, so depending on where you live, where you drive and for how long you plan to hold on to your car, that could be something worth bearing in mind.
ULEZ charges in London are currently £12.50 per day for non-compliant diesel and petrol cars. Birmingham and Glasgow are currently among the other cities in the UK with clean-air zones with others due to come into effect later in 2022 in Manchester and Aberdeen — almost certainly among the first of many more.
Should I sell my diesel car asap?
Not necessarily. If a diesel vehicle is and will continue to be a good fit for you, and you don’t have to pay low emission zone charges to use the car, then there’s no real reason to get rid of it.
When it comes to values of used diesel cars, although it remains to be seen what will happen the closer we get to 2030, thus far the value of used diesel cars hasn’t fallen off a cliff in the way that some predicted it would. That may in part be to do with throttled supply of new cars, due to factory closures from Covid-19, shortages of semi-conductor chips and the new war in Ukraine (a number of car maker factories are based in the region), but the signs are that there’s no need to panic about diesel car values.
According to figures released by valuations experts Cap HPI, based on a three-year-old car with 60,000 miles on the clock, the difference in depreciation levels between petrol and diesel models is marginal. An average petrol SUV will have depreciated in value from new by 56%, for example, with the equivalent diesel showing depreciation of 58%.
Similar figures can be seen across a range of segments with diesel city cars depreciating by 69% versus 65% for petrol models and just a percentage point in the difference between petrol and diesel cars in the executive class at 61% and 62% respectively.
There’s no indication that diesels will become more difficult to run or own in the coming years, and nor is there any proposal for an outright ban apart from the 2030 one on new petrol and diesel car sales. You will still be able to sell your diesel car, and indeed buy and run another used diesel, beyond 2030.
Given the fact that as yet there’s no real alternative to diesel as a powerplant for bigger, heavier vehicles such as those used for towing, values for these are likely to remain high.
That said, if you’re in the market for a new car there are a number of manufacturers currently offering generous scrappage schemes for older diesel cars, so that’s something to consider if you’re changing your car.
- If you were interested in whether you should buy a diesel car this year interesting, you may want to read our guide to AdBlue
- You may want to check out everything there is to know about the 2030 petrol and diesel car ban
- Top 10 petrol and hybrid cars to buy instead of a diesel
- BMW 3 Series updated for 2022 with exterior design tweaks and Curved Display dashboard
- Extended test: Mini Clubman 2021 review
- Lego Transformers Optimus Prime model actually transforms from robot to truck
- Rolls-Royce Phantom updated with reworked grille, 1920s-inspired wheels and Bespoke Phantom Platino edition
- Man who drove Maserati down Rome’s historic Spanish Steps was ‘following sat-nav’