Just got back from trip to France in the X5.
We did 1700 miles in 9 days & glad to report my X was faultless.
I got just over 37mpg (on OBD) travelling 450 miles to where we stayed taking it steady with a mix of 90kph to 130kph roads so well pleased with that, average came down a bit on way home as we were in bit of a hurry but over the 1700 mile trip the OBD is showing nearly 35mpg

Now the reason for my post, after the first fill up of diesel in France ( 1.29 euro's a litre ) my mates travelling with me in two other vehicles mentioned there was a lot of black smoke coming from my X when accelerating hard. Now my X has always smoked a little when using kick down which seems normal ? But after they mentioned this I tried a full on blast away from a toll booth & looked in the mirror, bloody hell

I didn't notice any drop in performance although there was four adults in the car & a boot full of luggage so it was a bit slower than usual.
I checked the oil etc in case it was the turbo but all was normal.
This smoke went on for the next two fill ups ( supermarket & service station ) but on Saturday I filled up with 90 litres of ''Super'' Diesel at a BP station ( 1.53 euro's a litre ) and the smoke was gone, or at least back to normal.
My question is, is the diesel in France generally less refined than that in the uk ?
It's a lot cheaper than petrol & cheaper than diesel in the uk.
I forgot to mention my X was remapped by BW Chiptune & I seem to remember when I was asking about getting it done they asked if I would be using the car abroad ( or maybe I've imagined this

Anyone else experienced this ?
Thanks for reading, Phil.