Go back 15 to 20 years and the only diesel powered vehicle you saw was under the bonnet of a commercial vehicle or a large luxury brand. Now even small cars often have the choice of a diesel engine.
Consumers are attracted to them for a variety of reasons. Low fuel consumption has long been the diesels’ strong suit, especially in larger SUVs where the difference between petrol and diesel engine consumption is at its greatest. The purchase price disparity between petrol and diesel variants has narrowed, and with some brands the difference is now less than RM15,000.
If you’re buying a diesel to save on running costs alone, though, you need to consider a couple of factors. Mileage – how far you drive – can have a big effect on the bottom line. If you drive less than the average of 15,000km per annum – let’s say half that, 7500km – over five years you will be around RM1500 worse off compared to the petrol equivalent.
And there can be some other ‘hidden’ costs, especially if you only drive short distances.
How far you drive, can have a big effect on the way your diesel engine behaves. If your diesel-powered vehicle conforms to the Euro 5 emission standard, then it will likely have a particulate filter built into the exhaust system. Its job is to capture and store black sooty particles, the sort you would normally see belching out from old trucks and some early diesel cars. At a predetermined time when you’re driving, the particulate filter will heat up and burn off the heavy soot particulates.
But if your daily drive is only around 18 to 25km, it may not be enough for the particulate filter to do its job, as it requires heat to perform effectively. Consult the owner’s handbook and there will be a process described on how the vehicle can self-clean the unit. If that’s not successful, then it’s a trip to the repairer and the attendant costs to investigate the fault. If a particulate filter can’t be serviced, replacement costs can be expensive and they aren’t covered under the warranty for that type of failure.
It’s by no means a common problem, but it highlights the need to check that your style of driving suits diesel.
Our tip – if you only drive your car a short distance, head to a highway and drive the vehicle fast while keeping to the speed limit for at least 20 minutes, which allows the self-cleaning process to be carried out.
