I think Tesla has swapped from 255 to 245 width tires, but don't quote me on this.
The images on Tesla's configurator are too blurry to get an accurate reading, but they're clear enough so that I can tell you the type of tire each wheel uses.
The 19's are 255/50 or 245/45 with Goodyear's Eagle Touring
The 20's are 255/40 or 245/45 with Goodyear's Eagle F1
The 21's are 245/45 with Pirelli P Zero's (ttothejizay has their own post on this)