Ask Honest John

Most recently answered additives questions
I currently run a 2006 Honda Accord 2.2 i-CTDi and have been using Shell V-Power diesel fuel exclusively. I was just wondering what your thoughts are and why you singled out BP Ultimate diesel as your...
Some 2-3 weeks ago you ran a letter about problems with diesel fuel blockage caused by the addition of biodiesel to standard diesel and lack of use of the vehicle. I have a smallholding and two tractors...
I normally add some lead substitute to the tank of our 1980's Series III Land Rover. The other day I didn't (because the garage didn't have any on its shelves and I then forgot about it). So with a full...
I booked my Honda Civic in for its first service since I bought it, mileage 13,000. I was asked if I wanted an engine flush for an extra £33. I asked what this was and was told they flush out all the oil...
My new Ford S-Max manual (p155) recommends using petrol "without additives or other engine treatments". Also supplied with the car is a leaflet saying "Ford recommends BP because BP fuels include additives...
I own a Toyota Corolla Verso 2.2 D4D. The Toyota dealer recommended that I not run the car on diesel purchased from supermarkets (do you agree with him?). Also, that I use an injector cleaner once very...
I took my Mazda 6 (2.0 litre petrol) in for its annual service to the local dealer recently and was advised to include a new petrol additive called TuneUp at a cost of about £15 (when VAT is included)....
I have a Skoda Yeti 2.0 Diesel with DSG. 5,000 miles a year, 40% of my journeys less than 5miles. Would a fuel additive reduce the chance of clogging and, if so, how often should I use it?
Today's diesel fuel is low sulphur - an EU requirement for polution control - but sulphur helps lubricate the fuel system. I have been told that by adding 2 stroke oil (1 to 200) to each tank of fuel this...
My Peugeot 406 coupe is missing its fuel additive tank. What will it do to the car and its performance?