Ask Honest John

Most recently answered dpf questions
I'm considering buying a Mazda CX-5, which I’ll drive for 8000 miles per year. You say the diesels should not be subjected to short runs if at all possible, but what is a short run? My pattern of motoring...
I am considering the purchase of a secondhand Jaguar XF or XJ about 3-4 years old, but from reading your various concerns about particulate filters, I am also concerned. My annual mileage is no more than...
I am thinking of buying a 2012 KIA Cee'd 1, 1.6 diesel manual. My mileage is approx 8000 - 10,000 miles per year, roughly 50/50 short journeys and motorway. I have been told if once a week I do 50-60 mph...
I purchased a brand new Vauxhall Corsa 1.3CDTi on 07-09-2012. Since then it has been back in the garage five times due to DPF related problems. It has currently been in the garage for eight weeks waiting...
My Vauxhall Combo van is suffering from a loss of power and black smoke. The engine light is also on and no garages can solve the problem. I have a suspicion that the DPF is not doing what it should, can...
A family member is selling their 2005 Volkswagen Polo 1.4 diesel. It has only covered 36,000 miles and has a full service history. I think it will be offered for around £3500 - is this a fair price?
I’m looking to buy a used car to tow a caravan with a gross weight of 1400kg. What diesel models/years do you suggest I look at that do NOT have a DPF?
The yellow 'engine block' light has illuminated on my Volkswagen Touareg diesel during a 300 mile trip to Cornwall. It went out a day or so later only to come on again on the way home at the end of the...
I am considering replacing my 140,000 mile Vauxhall Omega V6 with a Lexus IS. Can you tell me when Lexus first fitted a DPF to the IS 220d?
We have owned a 2007 Hyundai Santa Fe 2.2 CDI 7-seater for three years but recently it has displayed the engine management light. Our dealer carried out a diagnostic check and revealed it was a clogged...