On a bit of a whim, I decided to try a different brand of tires, Hankook. This brand runs about 70% of the cost of more conventional brands but are not as high rated in terms of performance or wear.
When driving on the tires, I generally found them to be just fine. I think only in one situation during their lifetime, I thought “gosh these tires are underperforming”, so from a performance point of view they served their purpose just fine.
During this experiment, I meticulously checked the tire pressure monthly and added air as needed and rotated them twice around 6K of mileage. But because of the pandemic and limited ability to travel, probably more driving was done on hilly and curvy roads than normal. These types of road are far more enjoyable than freeway or conventional straight and flat roads. But driving on steep grades and windy roads is hard on tires.
I was hoping the tires would last, but I went to have them rotated again at 16.5K miles, and they were completely worn out. All four tires measured 3/32 and the left rear inside sidewall was at the sketchy dangerous level. Again inside toe issues but at a tolerable level.
The last set of tires on my 19” wheels lasted 23K miles. The rough math is that the $/mile ends up being basically the same for both sets. When I had 21” wheels, the four tire sets averaged 16,400 miles each.
My new set of tires is now the factory Michelin primacy tires with a 45,000 mile warranty. I’ll probably rotate them as frequently but I doubt I’ll keep up with the super regular tire pressure checks. I wonder how long these will last.
TESLA OWNER 
Wow, that’s not a lot of miles. On my 2014 S, I got 50K on a set of tires. On my 2018 S, I’m on my original factory tires at 30K miles (42K total on the car but I use winter tires so not all go on the summer ones). I rotate every 5K and check air weekly. Even my winter tires on my original S got over 30K miles. I don’t know if its the slightly older car (I think you have a 2013) or what but you’re getting like 50% less miles on a set of tires…
I know it is crazy! I suspect it has to do with the grades I am driving down. My street has a 17% grade. I can’t figure out what else as I was meticulous with this set of tires.
I agree with Teslaliving. I’ve got 33K miles on my 2018 Model S and I’m still on the original tires.. Although, truthfully, I’m starting to think about replacements in the near future. I’m in WA and there are a fair amount of hills, but nothing crazy. I’ve also made the drive from WA to AZ and back twice. And I haven’t even rotated them! I’ve got a P100D and the Tesla folks told me the dual motor versions typically don’t need rotation until you see more than 2/32 of an inch difference between the front and rear tires. That hasn’t occurred yet. Of course, I also don’t accelerate quickly very often, so I’m sure that helps.
I have no idea why mine wear out so fast. My only suspicion is the grade of my street, but other than that I have nothing else left. I don’t drive aggressively.