Related topic if anyone wants to pick it up:
At VIR C&D used the stock run flats on the 335i and they recorded a time of 3:13.2. The Mustang V6 ran a 3:12.5. I can almost bet the Mustang V6 was wearing some good rubber at VIR. Here we see the 328i knock off 3 seconds from its time just by switching tires. It seems to me the F30's performance is underrated in every test we have seen given this handicap by the run flat tires.
Are S4s on run flats?
Streets of Willow times for reference
Looks like Randy owns Street of Willow too!