Tesla's excessive negative rear camber is only 10-20% of the tread problem, and is non-adjustable on stock camber arm. Excessive rear toe is 80-90% of the tread problem, and is also non-adjustable on stock toe arms. Then, heavy acceleration forces the entire rear subframe to move forward, further increasing the already huge rear toe, and no wonder the tires disintegrate.
Tesla's factory alignment specs are complete garbage. There are
no other production vehicles that spec 0.18 degrees of toe as an allowable value, yet every post in this thread that says "Tesla did my alignment" has attached a picture showing Tesla has their rear toe at 0.18 degrees, unacceptable.
Model S/X drivers with 21s have only 2 options:
1. Replace tires every 5-10k
2. Install aftermarket
adjustable camber and toe arms, and correct the alignment to sensible specs instead of Tesla's junk specs.
As
@Sam1 has already explained, 19s are much less (but not immune) to the bad alignments because of greater available sidewall flexing.
Anyone that doesn't believe this? Let me run your 21s on my Model S with aftermarket arms and corrected alignment. I drive like a bat out of hell, but I'll still get 30k out of your 21" factory Michelins (because I've got 45k on my tires already, with more remaining). I'm running -0.4 camber and +0.02 toe on all 4 corners.
