Do any of you have a preference for the type of diesel you use? Tesco's cheapest or a higher cetane index diesel. I use BP Ultimate.....I can notice a small improvement in engine response.

Cheapest I can find. Whenever I've tried the premium stuff I never noticed a thing. Doing a brim to brim check on MPG it was 0.7 mpg down on the previous tankful. Neither here nor there as a difference and certainly normal to account for slight differences in driving routes/style/weather etc.

My take is this. IF it made a discernible difference it would become law in the same way unleaded did to replace 4*.

It would be more to the point if bio or veg capability were to become law. That would open up a lot of choices and force some price competition.

One of the respected BMW tuning companies based in Milton Keynes did a study on super unleaded fuel suppliers and found that Tesco Super came out best, BP Ultimate did achieve higher increases in BHP but seemed to 'go off' after a couple of days and dropped down.

These tests were done on an M3 CSL (i believe, definitely an E46 M3 at least) and, from memory, you had to fill up a couple of times so the ECU could recalibrate for the increased RON over normal unleaded or other super you were using.

Having said this, I used to run tesco super as it was cost effective and it was a bonus that it did well in the test.

Now I don't know at which point Thorney Motorsport (the tuning house, & incidentally the guys who helped out Top Gear at their Britcar 24 Hour effort) got sponsored by Tesco BUT they have great respect amongst the 'M' fraternity.

On the fuel/performance side of things I would say if one want better performance have a remap as there are so many things, as MZPLCG said, that will affect performance such as general weather conditions and temp that differences in pump gas cannot accommodate.

Should have added - Cheapest I can find also...

Last edited by Dogman on 5th Jun 2011 9:58am. Edited 1 time in total

+1 with DOM, the cheapest i can find which is normally asda and with my asda credit card i get another penny off..

+1 with the cheapest. I did use to use super unleaded with the Porsche and with performance cars it may give gains, but with diesel and the fact that I dont drive the RR fast, I just put in the cheapest, which for me is ASDA as they are at the top of my road to!  Reformed

Cheapest I can find also but I THINK i notice a difference when using ASDA / TEsco that the TDV8 is noisier ?? But it might be in my head.

Sorry got to laugh drive a FFRR and you look for the cheapest available

I drive a Range Rover but I am not filthy rich! I have tried the more expensive diesel and it made no difference in mine, so what is the point in paying more for it, especially with fuel being so expensive. Reformed

It was meant as a joke … tongue in cheek ……………

I fill up with the cheapest fuel I can find.

I recently did several trips to Devon and back from North Gloucestreshire. Interestingly the cheapest fuel was in Cheltenham (At the time 132.9) When everywhere else (And I checked prices in Gloucester, Bristol, Exeter and in Devon) was up around the 140.0 mark. Don't understand why, just enjoyed the equivilant to 30p a gallon cheaper prices!

I was tempted to fill up one tank with premium Diesel to see if I got more MPG etc (But never did)

MICK wrote:

It was meant as a joke … tongue in cheek ……………

I had my "just woke up" head on earlier and wasnt with it! & I am tight anyway! Reformed

I don't think there really is much of a difference between them apart from marketing hype, so I always go for the cheapest I can find. The tolerance levels the car can take will never be tested with UK suppliers and the engine ECU will modify things to match.