Ask Honest John

Most recently answered fuel questions
Should I use additives in a 3.0 Jaguar F-Pace diesel, other than AdBlue?
I have heard that supermarket fuel damages the fuel injectors and its best to use non supermarket fuel - is this true?
What is the legal position on carrying in a private car a can containing spare E10 petrol? if it is legal so to do, what is the best currently available 'explosafe' can?
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...
A local company says it can adjust the fuel use of my Citroen C5 6 spd, 2.0 HDi, upping it 10% without risking any parts. I'm a slowish driver, mostly 2,000 rpm and have the car in eco, whatever that does....
Is it better in the long run to top up fuel at half tank on a regular basis or to refuel when almost on reserve?
A friend has suggested that I use the above but would welcome your comments. I drive a BMW 420i cabriolet auto and a Toyota Aygo X auto. I rarely use supermarket petrol and mostly use BP or Jet.
I drive a Skoda Fabia 2021, what type of petrol is best to use?
I have read about a device that plugs into the car under the steering column and claims to reduce fuel consumption by about 35 per cent. Is the claim valid? Is it safe to use? Seems strange that the technology...
Do you have any feedback on fuel savers that plug into a car's tuning system that are being marketed at the moment?
 

Value my car

Save £75 on Warranty using code HJ75

with MotorEasy

Get a warranty quote

Save 12% on GAP Insurance

Use HJ21 to save on an ALA policy

See offer