I have 41,000 on my Model S on the original 19 inch tires. I got the car in March, 2016. I measure the treads pretty regularly and I should get 50,000 out of these, easily. I have rotated the tires about 4 times, and I don't do it religiously based on mileage. When I measure the treads, I measure the outer, middle and inner of each tire. On all 4 tires, the outer and inners measure between 4 and 5/32s and they are all pretty even. All of the middle treads on all the tires are at 3/32s. I can't imagine this is an alignment issue because that would result in the outer or inner wearing faster, not the middle. The only thing I can think of to cause this is overinflation, and I consistently run with 45psi cold (although it does creep up while driving to 48 to 50, depending on temperature). Curious if anyone else has had this experience.