Ask Honest John

Most recently answered premium fuels questions
I have now run a Chevrolet Cruze diesel auto for over one year. Since Shell introduced "Fuel saver" diesel, my consumption has increased to 27.86 mpg average over the past 1,138 miles i.e. five tankfuls,...
On 2 December 2010 I bought a diesel MINI Countryman ALL4. This is the first diesel-engined car I have ever bought. I am delighted with it as a car. It is comfortable and the performance is lively and...
I have used Shell and BP petrol and diesel fuels for their higher detergent and lubricity respectively. Other than more power, what advantages do V Power/Ultimate offer to justify the higher price, compared...
Anybody else suffer flat spots at low revs in the Ford Focus 1.8 TDCI or find it easy to stall at low revs in first and second gear?
My Citroen C5 1.8 LX petrol has developed a fault. As I was driving along the motorway the little orange engine symbol lit up. The car drives and functions normally and the light makes no difference. Has...
This is a very important question as many vehicle owners suffer sticking vanes in turbochargers due to carbon build-up, which is very expensive to fix. Do any of the super fuels (V-Power, Ultimate or Excellium)...
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...
My Hyundai i10 is beginning to give me starting problems, intermittently. Its a March 2010 model with only 600 miles on the clock. I mainly do short runs but have taken it on a 40-mile long run at varying...
I have a Ford Mondeo 2-litre TDCi. I put some V-Power fuel in it last week and it started belching out black smoke and misfiring more than usual. On further investigation i noticed the large pipe near...
Do you think diesel additive is worth buying and using? Or would it be better to buy the premium fuel on the forecourts?