It would be great if someone could advise the potential cause of the below behavior.
The engine when still cold gives a nice acceleration feeling when changing from 1st to 2nd gear at 1500rpm. The MPG indicator stays above 20.
When the engine at normal temperature (temp needle in the middle) and performing same gear change on same revs the acceleration is poor with the MPG indicator going below 16.
I had a BMW specialist test driving it but he couldn't feel any performance issue.
I know I have the "sticky accelerator" problem which has been fixed only through "cleaning" by the BMW dealer.
Any advise is mostly appreciated.
BR / M