Speedo Calibration

[Martin4356111]

Morning all,

I just picked up my new Focus from the dealer on Tuesday. Yesterday I noticed that the analogue Speedo reads around 15 mph more than the digital one. 

Having done a couple of rudimentary tests (following my mate at 30 mph), it's the analogue clock that out, definitely by around +15.

I'm going to take it in tomorrow but have one question. Would this mean that the miles being added to the mileage clock would also be wrong?

Thanks in advance.