BP Ultimate surprising result.

It is appreciated that the engine will improve with age. HP will probably rise and mpg will get possibly better. The point I was referring to was the instant change. Not one over time.. It was within a couple of miles from filling up. A real sharpness about the pick up and the instant lack of any flat spot. Have used several diffent brands before but this is the first time of using a premium fuel. 

As I suggested...the fuel lines and pump etc wouldn't have cleared the original fuel in 'a couple of miles'?

It's always worth going back to the original fuel and seeing if the flat spot returns????

The last two company cars I had before retirement were both 1.7TDi Astra estates. On both of them the fuel consumption went from around 46mpg to over 50 at almost exactly 30,000 miles - like a switch. That has to be a software effect.

Come to think of it the two Vectra estates I had before that did the same thing!

If you want to try out one of the 'performance' diesels go to Luxembourg - you will still pay less for it than for supermarket diesel over here. I tried it out a couple of years ago on my last Passat estate and whilst it did run quieter and a little more smoothly IMO it didn't make anything like change that I expected that would justify the extra fuel cost outside Lux. Current price is €1.02/L for normal diesel and based on that I would expect the performance version to be about €1.09 - or 92p/L. Makes you sick doesn't it? 

There as been discussions on here before on using premium fuels a lot of negatives and some positive some saying it isn't worth the extra cost .I.ve found with our previous Passat 140 tdi and our present one the extra is justified especially when towing it definitely gives extra punch.Just driving solo will try and  do 1 in 3 fuel fills with the premium stuff .

I have posted before on BP Ultimate and premium fuels in general but I think it is worth repeating. Check out what BP say on their website and on their forecourts. Their claims are extremely modest and based around the fact that if you have an old "dirty" engine then running several tanks of Ultimate may give you an improvement. Note all the caveats and make your own mind up!

The surprising thing I found with BP Ultimate Diesel was with my previous car (Renault), the fuel consumption became worse, went back to Asda and it recovered, tried Shell V-Power and the fuel consumption improved, however not enough to warrant the extra price. Obviously all checked over a period tome with almost identical running. With car previous to the Renault, a Subaru Impreza WRX, BP Ultimate and Shell V-Power both improved the consumption. In my experience some engines like the stuff, some don't care and some hate it, you've just got to try them and see what's best.

One thing I have found since using premium brands / fuel is that when filling there is no foam. Unlike many supermarket fuels. Don't know if that would or would not have any long term effect. 

how do you see the fuel to know there's foam or not? 

I normally fill brim to brim. In Supermarkets the fuel foams out of the filler when getting near full but the likes of Shell etc does not. Something must be different. Just an observation. 

I fill both my petrol Smarts & diseasal R Class brim to brim with supermarket fuel ..... I've never seen any foam