Negative Camber in the Rear and Expensive Tires

[kishdude]

As a follow up, I just got my car back. After they put the new rear tires on, I told the SC to reduce the rear camber to the minimum allowable, and just by looking at the rear wheels, I can definitely notice a difference in the camber - it is much less. Hopefully this will reduce my tire wear. To be honest, I wish the SC would have done this the last time they changed my tires.

 

[CHGolferJim]

kishdude,

Reading through the whole thread will give you examples of different alignments and an appreciation for how toe can have a huge affect on tire wear. Luckily, toe is adjustable in the rear of MS. There are also Tesla's "Camber Bolts" the service center can install so that the resultant "bolt slop" can be used to bias for less negative camber.

Take heart that many have managed to have their cars adjusted to a more reasonable tire wear state. As qwk says, it can be done. There are also threads on Pilot Super Sports as a more cost effective tire alternative (assuming by your pricing that you are replacing PS2s).

and yes, excessive rear camber is a pain which is why I took steps to fix it when I collected my first car sixteen months ago.

I've enjoyed your posts on this topic. Do you believe a standard MS with 19" has this issue? I have the tire wear issue in my MB CLK320 and it is not fun to deal with. Thx.

 

[Dave EV]

As a follow up, I just got my car back. After they put the new rear tires on, I told the SC to reduce the rear camber to the minimum allowable, and just by looking at the rear wheels, I can definitely notice a difference in the camber - it is much less. Hopefully this will reduce my tire wear. To be honest, I wish the SC would have done this the last time they changed my tires.

Hopefully they fixed the toe. What a lot of negative camber does is just multiply the effects of toe out when there should be a tiny bit of toe in.

Do you have an alignment printout?

 

[qwk]

I've enjoyed your posts on this topic. Do you believe a standard MS with 19" has this issue? I have the tire wear issue in my MB CLK320 and it is not fun to deal with. Thx.

The issue is not limited by wheel size, although the larger wheels makes the problem worse.

 

[lolachampcar]

You can do a search on "informal tire wear" or something similar and you will find a thread I started to compile data on wheels, tires and wear. 19s did better than 21s. I suspect it was because (1) they were narrower so less mechanical leverage on the inside shoulder and (2) the side wall on the 19s is larger and more compliant allowing the contact patch to comply with the road better.

As drees pointed out, toe plus negative camber is a real killer. There are people out there getting 20K miles from 21" Pilots so it can be done.

 

[linkster]

(1) they were narrower so less mechanical leverage on the inside shoulder and (2) the side wall on the 19s is larger and more compliant allowing the contact patch to comply with the road better.

lola, might this be no. 3 ?

(3) the UTQG rating of the 19's (primacy/eagle) approximate 64% increase over the 21's (extreme contact/pilot ss/ps2)

Could all 3 contribute to camouflaging the issue ?

 

[lolachampcar]

absolutely; I did not even consider the wear rating which, of course, is a bigeeee

 

[jerry33]

lola, might this be no. 3 ?

(3) the UTQG rating of the 19's (primacy/eagle) approximate 64% increase over the 21's (extreme contact/pilot ss/ps2)

Could all 3 contribute to camouflaging the issue ?

It can but my 19" GYs wore very quickly on the edge, 13K miles, although the rest of the tread was barely touched. After a couple of alignments and the camber bolts the wear is much improved on the Michelin tires. It's toe-out that's the killer, camber only amplifies the problem.

 

[SarahsDad]

Add me to the list of negative camber victims. 11,000 mi and showing cords on the rear tires even though the wear bars aren't. Spoke w the service center and they said this is "normal", want to schedule a tire change, at my expense. Not happy.

 

[vgrinshpun]

Add me to the list of negative camber victims. 11,000 mi and showing cords on the rear tires even though the wear bars aren't. Spoke w the service center and they said this is "normal", want to schedule a tire change, at my expense. Not happy.

View attachment 50644

Ask them to do alignment check and see if alignment is within specs (see your manual on-line for the specs). It is almost certain that your alignment is out of specs (most likely negative toe and to much negative camber in the rear). Then tell them that your car is 8 months old and should be able to hold original alignment. Then tell them that tires are worn prematurely for the type of driving that you do, as you still have tread left and would be able to use tires if not for the side cord wear to to issue with alignment. I am surprised that SC wanted to replace tires without doing alignment - this wear is an indicator of out of spec alignment.

Note that it is normal for this type of rear wheel arrangement (negative camber) to have inside of the tire wear faster than outside, but it is not normal to show cords essentially outside of the tread area - this is abnormal wear due to misalignment.

Good luck, this approach worked for me - i got replaced my rear tires by SC at no charge - twice. First set wore down to cords similar to yours because of out of spec alignment at around 7,000 miles. The replacement tires lasted only 1700 miles and were replaced at no cost because the alignment was also out. See my earlier post for details:

Suspension settings and camber - Saving rubber

 

[Jeddi]

vgrinshpun I've had just about the same issue with my MS and now just ran through a third pair of rear tires on my P85+ with 17200 miles. SC had replaced the tires and aligned my car twice and it seems that each time the tires wear out even quicker than before. How long have you had most recent set of rear tires?

 

[vgrinshpun]

vgrinshpun I've had just about the same issue with my MS and now just ran through a third pair of rear tires on my P85+ with 17200 miles. SC had replaced the tires and aligned my car twice and it seems that each time the tires wear out even quicker than before. How long have you had most recent set of rear tires?

The second set was mounted on my 21" wheels in late November of the last year, but I had the winter set on my car at that time, so I did not use the 21" during the winter. I swapped my 19" winter set to the 21" some time in late March or beginning of April, and put only 1,700 miles on them before discovering inside wear on rears to the cords. There was an issue with the ride height in the rear as well, make sure to check the post I linked above.

I suggest that you go on-line to My Tesla, download the car Manual and print out the alignment spec sheet, if you have not already done this. As you can see rear camber is supposed to be -1.75 deg +/- 0.35deg. I asked SC to set camber to the lower (in absolute values) part of the tolerance band, i.e. Between -1.4 and -1.75deg, as this will minimize tire wear. The other part is to NOT have negative toe ( toe out) in the back, as it compounds the inside shoulder wear issue.

The "normal" wear of Mishelin Pilot Sport PS2 on the properly aligned Model S should be around 10,000 miles on the rear wheels and about 30,000 on the fronts.

I've put about 800 miles on the car since my last replacement of the rear tires.

 

[lolachampcar]

Those pictures serve to bolster my claim that it is safer to have the tires moved from side to side (yep, running inside on the outside) than it is to let the inside shoulder wear to the point of replacement.

Of course, the driving issue must be resolved but we also need to get as much as we can from the tires while everyone finds their own solution that they are comfortable with. My solution was arms and 1.3 degrees of negative. Another member went further with less camber (required new toe links as well). Some do not want to change Tesla parts. I can understand all those positions.

For reference, 12K miles on the rears with 40% tread depth across the tire. I expect about 18K before replacing. Lifetime is 290 W-Hr/mile in flat warm Florida.

 

[jerry33]

Those pictures serve to bolster my claim that it is safer to have the tires moved from side to side (yep, running inside on the outside) than it is to let the inside shoulder wear to the point of replacement.

I agree.

Of course, the driving issue must be resolved but we also need to get as much as we can from the tires while everyone finds their own solution that they are comfortable with. My solution was arms and 1.3 degrees of negative. Another member went further with less camber (required new toe links as well). Some do not want to change Tesla parts. I can understand all those positions.

For reference, 12K miles on the rears with 40% tread depth across the tire. I expect about 18K before replacing. Lifetime is 290 W-Hr/mile in flat warm Florida.

I suspect there will be a large market for these modifications once the warranty period is over and you're on your own. Unless, of course, Tesla comes up with their own modifications--wouldn't that be great!

 

[lolachampcar]

I think we are in that weird american liability world where the manufacturer can not do a useful and valuable thing for its customers because the customer will not take responsibility for the change. If Tesla has to take full responsibility for the change then the costs to redo all the stability control work price the effort out of any reasonable range.

Tesla already made the decision to use one geometrical model for both air and coil thus cementing high rear camber numbers for air. They are showing no indications of revisiting that decision.

Someone with a sufficient liability shield will step up and do full replacement links. It is way too easy to do it and the price of tires lets the seller value price the links. Someone would make a killing in CA if they did two hour drop off or wait service for $600.......

 

[dsm363]

Lolachampcar: could you update the first post in this thread with your current recommendations for what settings to ask for? Maybe one for air and one for standard suspension.

I guess you could further split that out into people who only want to deal with Tesla and those willing to go further into aftermarket solutions. Thanks! You are a great resource for and help to TMC members.

 

[youlikeadajuice]

Do you happen to know if a typical tire shop will mount tires with the inside facing out, or is this something you may have to hunt around to find a shop that's willing?

Those pictures serve to bolster my claim that it is safer to have the tires moved from side to side (yep, running inside on the outside) than it is to let the inside shoulder wear to the point of replacement.

Of course, the driving issue must be resolved but we also need to get as much as we can from the tires while everyone finds their own solution that they are comfortable with. My solution was arms and 1.3 degrees of negative. Another member went further with less camber (required new toe links as well). Some do not want to change Tesla parts. I can understand all those positions.

For reference, 12K miles on the rears with 40% tread depth across the tire. I expect about 18K before replacing. Lifetime is 290 W-Hr/mile in flat warm Florida.

 

[Madartist]

For reference, 12K miles on the rears with 40% tread depth across the tire. I expect about 18K before replacing. Lifetime is 290 W-Hr/mile in flat warm Florida.

Bill, I'm in awe of how you're able to achieve such a low Whr/mi on a P85+ with 21" wheels. I don't think I drive aggressively. Yet, the best I could manage is 327 Whr/mi.

 

[linkster]

I think we are in that weird american liability world

Someone with a sufficient liability shield will step up and do full replacement links. It is way too easy to do it and the price of tires lets the seller value price the links. Someone would make a killing in CA if they did two hour drop off or wait service for $600.......

Yes. I actually, wanted to be a Mid-Atlantic installer of UL's. I even made arrangements with my local shop where I, and ONLY I would drive the S's onto the rack and wait inside the car (may help in a small way to duplicate actual loading) while rear toe was reset. This install was quickly dismissed as liability issues surfaced. WRT to the ease of install, it was just as easy as my fun little DIY HPWC install.

 

[lolachampcar]

I work with a couple of shops I've known for many years so those types of questions do of come up (should or should we not do XYZ). I'm not sure how your average shop will respond to inside out. I suspect it depends on how much they know about tires and asymmetric tread patterns.