Diesel particulate filters - everything you need to know

Your car's diesel particulate filter can be the cause of seriously hefty repair bills. We explain what it is, what can go wrong and how to maintain it...

Diesel particulate filters - everything you need to know

Should you buy a car fitted with a DPF?

The costly repair bills for DPFs that some car owners have experienced have raised concerns among car buyers, prompting many to ask if they should buy a car with a DPF.

Whether you should choose to buy a diesel car with a DPF fitted depends on the amount and type of driving you will be doing.

If you do the majority of your driving at urban speeds and hardly ever take your car on a dual carriageway or motorway, you’re better off choosing petrol over diesel, saving yourself from potential hassles and extra expense.

Also, if you cover less than 12,000 miles a year, you're probably better off with a petrol car. Diesel cars are generally more expensive to buy new, and it will take a long time for the improved fuel economy that they offer to make back the extra money you spent when you originally bought the car.

DPF warning light

If you do a lot of faster driving, you should have no problems with a car with a DPF, though, as long as you follow the recommendations in the car’s handbook and pay attention to any warning lights.

If you’re thinking of buying a second-hand diesel car with a DPF, bear in mind that these can last up to around 100,000 miles if cared for properly. After the car has exceeded that mileage, however, you could be looking at paying a large amount of money for a replacement filter.

Can’t the DPF just be removed?

It’s illegal to drive a car that was designed to have a DPF without having one fitted. This is because your car will no longer meets its emissions standards.

Since February 2014, checking the presence of a DPF has became part of the MOT test procedure. All cars that are designed to have a DPF now get inspected for one, and its absence will mean an immediate failure.

If you’re considering buying a used diesel car that you suspect should have a DPF fitted, make sure you ask the owner if it has been removed and check that the car has a recent MOT test certificate.

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