Re: OFFICIAL: New 991.2 GT3
When I was in Zuffenhausen at the factory I was asking exactly that question the tour-guide (you can argue this of course) - but he said every GT engine is tested with a "gas" to check for leaks (a machine then sniffs tiniest cylinder leakages ) once this is a pass and hot test is done it needs approx. 500 km run in period only - after that it's all about warming it properly and off you go.
I think the tolerances are so small in these days that running-in is less important than making sure you wait until the oil has 90 degrees. I keep repeating this here - but I see this every morning from my neighbourhood that people come out of their garages and rev the car way to high after less than 1 Minute running only...never understood this never will