Originally Posted by BeamerandBimmer
. When you go to turn in your X5 at the end of lease BMW requires that you return it with the correct size run flat tires.
That is a good piece of information. In that case, OP should definitely keep the factory run flats on the 19" M Sports and pick up a set of winters, like those on CL above. Added bonus is you'll be able to sell them again yourself whenever you return the vehicle.