Martynn Randall is technical editor at Haynes and has been with us for approaching 30 years. He's written more than 60 Haynes publications and has owned more than 85 cars and 60 motorbikes... so far!
New year, new start. Looking forward, not back. But as Carl Sagan once said: “You have to know the past to understand the present.” And it’s with this in mind that the Society of Motor Manufacturers and Traders (SMMT) uses the start of January to release all of the new car sales data it’s garnered from the previous year.
It certainly makes for interesting reading. For a start, company car fleets were entirely responsible for the fact that the market grew in 2024, because demand from private buyers was down by almost 9% on 2023.
On top of that, and in a stark contrast to a decade ago, petrol is king by some margin. Over the entire marketplace, petrol-engined cars took 52% of sales, while the next most popular propulsion system was the battery electric vehicle (BEV), which took 19.6% of the market. Hybrids (HEVs) follow on 13.4%, then plug-in hybrids (PHEVs) at a little less than 9%. But what of diesel? It was the most popular fuel 10 years back, but last year it was down to just 6.3% of the marketplace. Talk about a fall from grace.
Should I buy a diesel car?
Are we right to have shunned diesel so completely? I’d suggest not, because there are still lots of situations in which diesel would be preferable.
For example, if you’re a high-mileage driver who does a great many motorway journeys, diesel would be better for you. A diesel car has greater mid-range torque than a petrol, which makes it more relaxing to drive when you’re just cruising along, on top of which it is far more economical than a petrol. And a pure diesel car isn’t hauling around heavy hybrid kit that doesn’t contribute much to proceedings on motorways, so is usually better on motorways than hybrids.
Yes, diesel fuel tends to be more expensive than petrol, but if you do enough miles you’ll soon make up the difference in your lower fuel bills, simply because you won’t be filling up nearly as often.
That strong low- and mid-range torque generated by a diesel also makes it ideal if you have a caravan or trailer to tow, because as long as you keep within the ideal 85% car/trailer weight ratio, a diesel will shrug off the extra heft when it’s hitched up.
What about ULEZ?
It’s tempting to think that diesel and low-emissions zones (LEZ and ULEZ) in cities such as London and Bristol simply don’t mix, but that’s not true. If the engine in your diesel vehicle complies with Euro 6 emissions standards, you can drive into a ULEZ with scarcely a care in the world. Bear in mind, however, that ULEZs are different from the London Congestion Charge – that applies to everyone except motorbikes and EV owners, although even the latter will have to pay after December 2025.
Haynes can help you look after your diesel car
Yes, as with everything, diesel is not perfect. This is because a diesel car used for the wrong type of journey will eventually have a hissy fit; diesels used for only short urban journeys are prone to clogging up their particulate filters, while a badly maintained diesel will end up with water in the fuel filter. That’s why it pays to keep on top of maintenance, just as you would with any vehicle.
And the good news is that every Haynes manual and Autofix product gives you recommended service intervals for your vehicle. If you’re using Autofix, just type in your car’s registration number and we’ll do the rest. Or you can invest in a Haynes manual, which will give you an indication of when to do various tasks, and will also give you an in-depth explanation of how to carry them out.