Urban battle
The major car brands continue to insist that early failures of their diesel particulate filters are a form of owner abuse. Many are then refusing warranty claims on DPFS.
They justifiably claim diesel vehicles require at least one ‘hot’ run every week at freeway speeds, under load for at least 20 minutes, to instigate what they call a passive regeneration within the blast furnace of the DPF. Too many owners, they say, don’t read their owner’s manuals and stop/ start, short, cold runs in an urban environment don’t get the filters up to operating temperature.
Supporting that claim are case studies Wheels has seen of citybased European marques with low kilometres but filters blocked by 85 percent.
One BMW customer drove from Bondi to Maroubra in Sydney every day (a distance of maybe 15km) and presented with a blocked DPF at 60,000km.
On the flip side, service centres are also seeing failed DPFS on country cars that routinely log plenty of long, hot runs. In what may be a pointer to the future, only one company, Subaru, tells customers their diesel Forester and Outback models are not well suited to prolonged urban use.
The bottom line here is if you do the school run and the shopping, rarely leaving the city limits, you are much better off with a petrol engine. It will save money too, given the hefty upfront price premiums charged for diesel models and the ongoing maintenance issues. No pricing provided although independent service agents showed Wheels invoices for an X5 DPF at $5126 plus labour.
BMW says, “our particulate filters are maintenance free and are designed to last as long as the vehicle.”
No response on carbon build up.
Prices range from $2200 on a Ranger to $2600 on a Mondeo, plus labour. Ford says its DPFS are designed to last the life of the vehicle and “should therefore be of no concern to the new vehicle buyer – or the second or third, for that matter.”
No response on EGR carbon build up.
Fiat Chrysler Australia quotes “in excess of 150,000km” as the expected service life of its particulate filters – albeit with the usual riders from the warranty department. “Poor fuel or oil will very quickly contaminate a DPF.” A replacement for the company’s Alfa Romeo Giulia is priced at $9602. With labour and coding costs the retail bill could be expected to comfortably top $12,000.
The Jeep Grand Cherokee filter is a $5409 item and the Compass $7693. The company has no service recommendation for any decarb of the inlet system/egr.