diesel cars | Ask Honest John

Ask Honest John

Most recently answered diesel cars questions

Our car's DPF is blocked. I've have tried regenerating it by running it down the motorway, but it's had no effect. Is there anything else I can do?

Is Shell fuel really that much better than supermarket fuel?

I've always used Shell V Plus diesel in my Range Rover TDV8, with 160,000 miles on it. My neighbour said it was a waste of money, so I switched to Asda diesel. My car now has worse fuel economy and runs...

Is buying a secondhand diesel a good idea, considering impending restrictions?

I would like to purchase a 2014 or 2015 Audi SQ5. For those years, they only come in diesel and my budget doesn’t stretch to the newer petrol versions. Is this a good idea, considering the new MoT regulations...

If you could buy any car, what would you choose?

I'm a field service engineer and I'm looking for a new car. If you could buy any car (estate, saloon or hatchback), what would you choose? It would have to be a diesel though.

I'm faced with a huge bill for turbo issues with my diesel car - should it be repaired under warranty?

I have a 2015 Vauxhall Insignia. I’ve only had the car just over a year, but a couple of weeks ago it broke down with white smoke belting out the back of the exhaust. The car is now at Arnold Clark. I...

Will the new MoT changes affect my diesel car?

I have a 2008 Volkswagen Golf 2.0 TDI. It is not fitted with a Diesel Particulate Filter (DPF) as standard so how will the May 2018 MoT changes affect this type of car?

Is buying a Euro6 diesel a sensible idea right now?

I'm looking to buy a 2016, second-hand, Euro6 diesel Hyundai Tucson for around £22,000. I want to keep it for five years or more. With all the confusion surrounding diesel cars, is this a sensible buy?

Should I buy a diesel car?

Is it smart to buy a diesel car?

I put AdBlue in my diesel tank - why do manufacturers put the caps so close together?

I've accidentally put AdBlue in my diesel tank, which seems to be a really bad thing (possibly worse than petrol in a diesel car). Why do Renault put the filling caps so close together? It's a fundamental...

I read that engine oil is contaminated by the DPF in 4x4s - is this the case with all diesel cars?

I read in a recent 4x4 review that the engine oil is quickly contaminated by the DPF. Is this the case on all diesel engines with a DPF, and can it affect the life of the engine?