Ask Honest John

Most recently answered diesel questions
Are new diesel cars generally being phased out?
I live in Spain (Mallorca) and used to have a 2014 Porsche Macan Diesel up until three years ago when we emigrated. I'd rather like to replace it but diesel examples tend to be high mileage (though cheaper...
Which or what type of additives should I use with lesser brand diesel fuels and how frequently?
Should I use additives in a 3.0 Jaguar F-Pace diesel, other than AdBlue?
What are the advantages/disadvantages of diesel over petrol for a ten year old car?
My local BP garage is still charging £1.55 per litre for their cheapest diesel, much more than any prices mentioned in the article (although in November 2023 it was 10p more at £1.65). Why would BP be...
We rather need to replace our high mileage and well worn 2004 Ford Fiesta. Still good to drive and almost completely reliable apart from troublesome front springs. Problem is we live in the sticks, nowhere...
I want to buy a used car for my company. How to work out the fuel / electric cost so I can compare?
I have noticed two types of diesel fuel on some forecourts. What is the difference please? Which has the longest shelf life?
I'm looking to buy a Citroen C3 Picasso, it's a 2015 diesel, and I was worried I may not do enough miles in it to keep the DPF healthy. I'll be doing about 8000 miles per year and the majority of driving...