Tyres on new 2008 VW Golf GT Sport 140

[gorty]

Bit of a mundane question, I'm trying to figure out the tyre history of my new car. I bought it with ContiSportContact 225/45/17's on the front and Michelin Pilot Primacy 225/45/17's on the rear. 18K on the clock, front has 7mm tread, rear has 6mm, both tyres made in Germany. What tyres did this car have when it left the factory? I'm guessing these tyres have about 8.5-9mm of tread when new. Are any of the tyres the originals, forum post suggest 20K for fronts, 40K for rears. This car is known for is frugality on fuel, I've just realised the tyres cost more than my motorbike, but they go further I suppose, just hope they don't puncture.