Ask Honest John

Most recently answered diesels questions
I have a Peugeot 306 HDi and am having problems starting it. It takes long to start when cold and warm but it's not as bad when warm and once started it ticks over fine.
Regarding latest EU emission regulations for diesel engines, could you please give us more information on the subject of the particulate filters being adversely affected by repeated short journeys? I have...
I always keep a couple of gallons of diesel as a stand by, but have not used it for about four years. Can I use it now or is there a limited time before it deteriorates?
In January this year we bought a new 3-door Polo SEL 1.6 TDI, downsizing from our long-lived, and immensely practical, Saab. In most respects the Polo fits our present needs very well indeed and we have...
What is your opinion of plug-in diesel upgrades kits for increased mpg? Bearing in mind the high cost of diesel, are they worthwhile? How many miles would it take to recoup the initial layout cost? If...
I bought a 2-year-old BMW 118d last May from the local BMW dealer. It is a fantastic car, but the stop-start function didn't work from day one. I reported it and waited until now to make sure there were...
It is apparent that the dual mass flywheel and clutch is known to give problems with some drivers (including myself) with the Jaguar X-Type 2.2D, but this would not appear to be the case with the 2.0D...
I bought a 2008-registered BMW 520D from a showroom and asked if it had the 177bhp engine fitted from September 2007. The sales manager confirmed that it did, but now we have owned it for three months...
I’m no great fan of the EU, but I think your reply to GR of Warrington blaming them for the clogging of particulate filters was a bit off the mark. Yes, the EU called for better street-level air quality...
On 2 December 2010 I bought a diesel MINI Countryman ALL4. This is the first diesel-engined car I have ever bought. I am delighted with it as a car. It is comfortable and the performance is lively and...