That model isn't even going to be available in the U.S. until next year and has not been tested by Sport Auto. You can not use a Nissan supplied time against one run by Sport Auto. Porsche claims a 7:18 for the GT2 RS. That is still faster than the time Nissan claims for the now twice upgraded GT-R so I don't know what your point is.
Originally Posted by Z K
Your tire assumption is incorrect too.
I'll stop you before you dig yourself into an even deeper hole. Treadwear ratings between tire manufacturers are NOT comparable. An 80 rating by Michelin can not be compared to a 200 rating by Dunlop. Each manufacturer interprets the UTQG their own way. Furthermore, it is erroneous to suggest the GT-R is somehow "undertired" compared to the competition. Dunlop has optimized runflats specifically for the GT-R's weight and contact patch. Swapping for supposedly stickier tires on the GT-R hasn't/won't yield faster times because they don't have the sidewall strength.
2008 E90 M3, Jerez Black, Black Nappa, Brushed Aluminium, 6-speed, Premium, Tech, Cold Weather