I'm about to order summer tires for a 20" staggered setup for Model S. Front is a no brainer: 245-40-20. Rear is a bit more complicated (we're talking about a 10" rim): Tirerack recommends 265-40-20. T Sportline recommends 275-40-20. These are 2-3% bigger than OEM. Others recommend 275-35-20. This is almost exactly the same circumference as the OEM setup. However, you don't benefit from the higher tire profile (this is one reason to get away from the 21" turbines). What would you recommend? Why?