On the additive front, and for what it's worth, the car does run noticeably smoother with Millers diesel plus, - And the fuel consumption is better.

I've recerntl been getting about 550 miles between fill up and the low fuel light coming on,, at which point about 45 litres is needed for a fresh fill up.

It was eventually discovered that the problem was a brand of supermarket fuel, which contained silicon and was having a damaging effect on the oxygen sensor. It was even reported on national news bulletins and a large number of vehicles across the country were affected.

This was a well documented one off and very unfortunate incident that only affected cars in a small geographic area. The cars affected were repaired by the retailers (Morrisons and Tesco from memory). It also affected some small retailers as well. This fact was never publiced anywhere near as fully as the cars where the fuel came from supermarkets and I did wonder at the time if the small retailers acted as honourably as the supermarkets did.

The supermarket fuel debate has been done to death on just about every forum but here are the facts as I understand them.

All fuel in the UK regardless of where it is being retailed comes form a small number of depots.

Allegedly additives are put into the fuel at the point the fuel is put in the tanker and these mystery additives vary from retailer to retailer.

Almost 50% of fuel sold in the UK comes from supermarkets. If it was as bad as some people insist dead cars would be littering the roads. Where I live ASDA is the only large fuel retailer in town, bet it has well over 50% of sales and all the taxis in town get thier fuel from there. Don't see many dead taxis.

I have been using supermarket fuel (petrol and diesel) pretty much exclusively since the mid 80's. Never had a single issue in all that time. When I am forced to use posh fuel our cars do not run any better or do more mpg. Its all in the mind of the people who have to convince themselves its worth spending more on a branded fuel.

On the ouskirts of town there are small Shell and Total filling stations. In the past I have seen plain tankers leaving both of these sites and then going to ASDA. Proves to me you will get exactly the same fuel form whereever you buy it.

I appreciate I will never convince those people who believe what they ahve been told over the yeasr Bu I for one will not be wasting a single penny of my money on this supossed better fuel that in truth is no different.

Not being funny Skidpan and please correct me if I'm wrong but you do strike me as being more of a DIYer rather than someone who has spent all their working life in the motor trade,

You don't need to work in the motortrade to know if a car is working OK or not. I have been driving for 40 years now and can assure you I am as sensitive to small changes in my cars as any seasoned mechanic, I should be, I drive them all the time.

So in my opinion I have lots of experience.

But some muppets would never know if a car has a problem or not, witness the number of cars with easy to check things like bald or even flat tyres on the road.

For what its worth I have built 2 Caterham 7's from scratch. The car I have now started life as a 4 speed X-Flow carburettor powered car and is now a 5 speed, Zetec engined injected car. All the work was done by myself including making a number of parts and the fitting and mapping of the fuel injection. The car is now 22 years old and has never been touched by anyone other than myself except for the annual MOT, which it has never failed.

I think that qaulifies me as being a bit more than a DIYer. In truth I have far more practical experience than most of the spotty kids working in garages who only know how to do basic repairs or even some of the gorillas whose toolkit only contains a big hammer and a large dose of brute force.

As for AA patrol men I had one work for me several years ago. He had to leave his job (according to him) because knee surgury made it impossible for him to carry on so he came as a delivery driver. When we spotted his previous experience we thought it logical to pass him some of the simple maintenace duties and managment of the vehicles. He was either thick, useless or a liar. If all AA patrols were like him they would go out of bussiness.