“The wear has anything to do with camber”. Camber is inarguably associated with abnormal wear, in general. All one needs to do to understand the relationship easily, is to examine what might happen at an extreme ridiculous example… let’s say, -45 degrees of camber. One could argue, and I suppose you do, that in our current situation, camber does not play a role. I don’t know whether it does or not, but from a physics perspective, it certainly *could* be related.
You are aware as well as I am that this is reductio ad absurdum. No one is talking about stanced cars here. The discussion is revolving around what are typical camber ranges on street driven cars. Within that framework, reducing the degree of negative camber will almost always impair handling to some degree. I say almost always because I’m sure someone can find some edge case and then claim that is a complete and utter refutal of the argument.
It would be highly unusual for camber to cause wear such that it would cause completely even tread wear and then separation at the inside edge. That seems much more likely to be tire defect.
“That the wear has nothing to do with the Tesla-spec PS4S despite those being the only tires to show this issue”. The issue certainly could have something to do with the tire itself, but given the failure mode, I believe it to be very unlikely to be a tire failure. Also, since these tires are optional on the plaid, it would be difficult to disentangle all of the variables associated with the failure without doing some experiments on other vehicles.
Sure, but what we do know is that the Plaids (and LRs) on the 19” wheels/tires do *not* manifest this issue. That seems to be handwaved by many including
@Sam1 despite the alignment being identical between the two. If this was a toe issue or even some combination of camber/toe, the 19s should exhibit *some* irregular wear, even if you accept that the 21s are hit worse due to their lower profile nature (something I am not convinced about as the 21s are not particularly low profile compared to tires on other vehicles within this class).
Also to note, I do not claim to precisely know what the issue with the Michelins is. Only that I do believe there is an issue with those tires, and that perhaps said issue can be mitigated with a less aggressive alignment, even if the root cause of failure is the tire itself.
I can only speculate as to what the problem with the tires is, if that is indeed the issue. Perhaps load rating (the Michelin 21s have a lower load rating than either the all season or summer 19s offered). But that is conjecture on my part, and I do not claim that is definitively the issue.
“That $2k on camber arms is needed to correct improper toe.” I don’t think anyone is claiming this. Toe is adjustable on a stock 2023 Tesla Plaid, and if anyone thought that the problem is exclusively toe, they would simply have the toe adjusted. People (like me) buy $1,300 adjustable camber arms to have the ability to dial in camber, not to correct improper toe. Perhaps you are being a bit sarcastic with your statement and I am taking you too literally; one of the dangers of being an engineer with a Ph.D. I suppose.
Cool, you have a doctorate, so do I. Just a lowly MD in my case. Nevertheless, if you go back through the 73 pages in this thread, there are several that claim the arms are de facto required to fix this issue. Far too many to list out here in the post.
“That reducing negative camber won’t have a negative impact on handling, all else equal”. This statement is overly broad. There are, inarguably, cases where reducing negative camber improves handling… think back to my corner case above. Camber changes, whether negative or positive, can improve or degrade handling depending on the state of camber on the vehicle in question.
Addressed above. My argument was and remains that if you take a given car, reduce its camber by a degree (or any other value you pick), it will handle worse (to be more precise, it will have less grip when cornering). That does not mean camber will be the sole factor to determine how well a car will handle (that is to say a Model S will not handle better than a 911 despite apparently having more camber), and that is also not to say that setting an absurd degree of camber like -45° will invariably improve handling.
There is, I think, a tendency in online forums to overly simplify arguments in order to make a point. People do not have the time, or the knowledge, to write a dissertation quality response to an online post. It is much easier to simplify and use anecdotal evidence to support the simplified argument; this almost always results in errors.
Joe
Sure. And that is what the entirety of this thread is. I do not see compelling evidence that this problem is purely a function of bad alignment.
