Ask Honest John

Most recently answered diesel particulate filter questions
I've had to pay my Toyota dealer £275 to regenerate the DPF and change the oil on my 2015 Yaris diesel. I used Millers longlife ACEA C2 5W30 at the last oil change, but the dealer says this is wrong and...
My Skoda Octavia 1.6 diesel is six months old and the DPF light has started to come on. I use it for daily commuting and school runs. About once a week it gets a 200 mile or so business trip mainly on...
The manual for my Ford Focus Estate 1.6 TDI instructs to occasionally run in lower gears at high revs but does not say how high for the revs or over what distance. In 10k miles, I am not aware that DPF...
I own a SEAT Ibiza ST, which I bought new in 2010. After about a year of owneship the DPF light started coming on, requiring me to take the car for a run in third gear on the motorway for about 20 miles....
I own a 2010 BMW 5 Series. In recent months the car has reported high oil levels after a DPF regeneration. I presume fuel is now mixing with engine oil. Is there a fix for this problem? Also the BMW...
I am thinking of buying a Nissan Qashqai diesel for towing my 1300kg caravan, but have concerns about the DPF. Would the 1.2 petrol engine be powerful enough or should I go with the 1.6 diesel?
I had a DPF delete done in 2013 on my Ford Focus diesel. All was well until late 2014 when the powertrain light came on. I had the ECU checked, but no codes showed up. Since then I've had my local remapping...
I'm thinking of buying a Mazda 6 (2011 model). I love the car but have heard of a few DPF issues with this car. Did this model get improvements to the DPF or is there anything I should look for?
Is it true that some VAG diesels have been built using the "Manifold in Head" tech that other makes (Renault) have used to good effect in reducing DPF problems?
My Volvo V50 (2006) keeps slowing down on long stretches of the motorway, after an hour or so, and displays a sign saying "Engine System Service Required" on the dashboard. No garage, mechanic or anyone...