Q7 21" Tires
#2
I had the same problem on my 2013 q7 sport s-line. 21'' wheels from audi, not too many tire manufacturer make that size, only high end (pirelli, yokohama). And they only make really sticky compound to maximize handling and grip, therefore not so great mileage out of them. Tire guys suggested to replace my 21'' wheels with 22'' wheels, more standard size to fit tires on. Hope this help
#3
I have been researching this problem (taking delivery of a '18 Q7 Prestige w/black optic package and 21in wheels soon). The above response is my best discovery as well. I would have opted for the 20" or 22" where there are all season offerings, but that is a really expensive change out...so that seems to be it unless I missed something.
#4
look here Audi Q7 tire size for all wheels front and rear axles 2005-2017 | Cars Tire Size ? Dimensions For All Wheels Front and Rear Axles . i hope this was useful for you.