The pictures as published by Tesla in the Plaid and Plaid+ Configurator clearly show the proposed tires size.
The 19" Tempest tires are Pirelli P Zero 235/45 R 19. The 21" Arachnid are Michelin Pilot Sport 4S 265/35 ZR 21 and is 20mm wider than a 245 tire.
Interesting is the 19" 235 which is 10mm smaller than the 245 tire normally found on a Tesla Model S. A 235 tire or a 265 tire means 30mm difference. For the tire to visually snap to the outside line of the body a spacer must be installed. Normally only one tire size is advised for a car.
