Made the mistake of putting Sainsbury's diesel in my 147, which created tons of black smoke.
I refilled it with Shell V-Power (its usual drink) and added a cleaner, but there's some noticable flat spots in the throttle (if it was petrol I'd suspect a plug/ignition problem) and still loads of smoke.
This morning I got the engine warning light and engine control system failure message.
Hmmm Why "automatically" assume that putting in supermarket diesel a sole responsible factor for a fault, 6.5 million diesels in the UK use the supermarket stuff on a regular basis yet we dont see 6.5 million of them coughing out plumes of smoke
You have pretty much answered your own question in a round about way my friend "I refilled it with Shell V-Power (its usual drink)"
Now I am not going to enter into a full blown discussion about the pitfalls and merits of different fuels etc.... That topic has been done to death!
All I will say is V-Power and their Ilk have additives and extra detergents in them (fact)... Good or bad is up to the individual.
So over time you engine starts to "depend" on them, so when you end up going back to normal stuff, that the car would have run on quite well in the first place I might add (it was designed to run on normal diesel afterall)... It now doesn't like it... Your engine is now a "junkie" for the additives!
The question is: do they put these additives in to get your car hooked so you cant go anywhere else?
Or do they really work and its just plain bad luck with a bad batch of fuel?
Thats an open ended question!
Just like using ether or easystart on a difficult to start diesel engine, use it very, very occasionally, its fine... use it all the time, it wont start without its fix...
It's called killing with kindness.