Miles on the car. Given how the article states that the tires alone are good for 5k miles and cost $1600 to replace, that's 32 cents per mile just for the tires. If you're going somewhere far enough away that it's worth your money to fly instead of drive, it'll also be worth your money to rent a local car rather than have your Tesla drive to meet you.

I am not a Tesla owner, so please correct me if I got the cost/mileage of the tires wrong.