[FatTire]

I agree with WR11, the 245 45 19 works great and fits the wheel well better.
The overall diameter is 27.7 and is the same diameter as the 245 40 r 20/ 275 35 20 which I will be running on my 550 xdrive. BTW one can run staggered wheels on the xdrive. Just make sure all your tires have the same diameter.

My last 3 BMWs speedmeter read 2-3mph slow....tested by radar and GPS and the inch taller tire actually corrects the true speed. I've talked to several Dealer Service Depts about this and they say that the factory is within the margin or error 3-5%.