Ask Honest John

Most recently answered additives questions
My daughter has used Lucas upper cylinder lubricant as a fuel additive with her Honda Civic 2.2 cdi and experienced much better mpg figures. Would this be OK to use with my Audi A6 3.0 se TDI quattro automatic...
I have a 3-year-old Hyundai Getz 1.1 petrol. The 'Malfunction' light is occasionally coming on and when I accelerate the power is "lumpy". The handbook indicates it could be a faulty component with the...
I am given to believe that the actuating rod on the turbo of our Ford Focus 1800 turbodiesel is sticking with the wastegate held open, causing the engine to run with greatly reduced power. I understand...
My 1997 Escort GTI keeps losing power. When I start it up it idles fine, but when I press the accelerator it chugs and splutters when it is cold. Took it on a run yesterday and intermittantly it loses...
I have had problems with misfiring, loss of power, and red engine management lights coming on on two cars which where filled with unleaded petrol at a supermarket. One of the vehicles has needed to have...
I have a 06-reg Kia Rio which is displaying a sign saying "Check" which, according to the handbook, relates to the emission control system. I have not detected any change in the performance of the car...
Do you think diesel additive is worth buying and using? Or would it be better to buy the premium fuel on the forecourts?
My 2007 Mercedes-Benz E220 CDI with 49,000 miles sometimes used to feel like it was trying to lurch forward while moving at low speed, without any change on the accelerator. For the last month it is shaking...
I recently added injector cleaner to half tank of diesel in my 51-plate BMW 320d. I drove it as per normal, refuelled, and then started noticing blue smoke when at traffic lights. Performance seems ok....
My Vauxhall Zafira comes up with the warning light for the particulate filter, and a couple of times has almost ground to a halt. Will hard driving help and for how long? Is there a fuel additive that...