HI dose any one know how to tell the car its now got 16 inch wheels on it from the 15inch which was on it ,changed because tyre are cheaper for instant now the  rolling radius is out i dont think its got a speedo drive sensor 

from 2056015 now 2055516

It can be done using VCDS, I think there is a setting for Winter Tyres but I'm not sure you can actually select the tyre size, I think perhaps its a warning not to exceed a certain speed, worth a look though.

its a warning not to exceed a certain speed look at that cheers 

There is no need to do anything, the difference is 0.78%.

The you go to one of the comparison sites you get the result below:-

 

This is less than the error in your speedo and the variations due to tyre wear.