steve841
Active Member
I'm not saying its right... I just have dealt with similar on previous cars....and that was the response I got.
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Negative Camber in the Rear and Expensive Tires
- Thread starter lolachampcar
- Start date
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- Driving Dynamics Model S
I'm not saying its right... I just have dealt with similar on previous cars....and that was the response I got.
wow in such short miles you can worn out tire at this level.
I know most of the $20k cars are install with bridgestone (lower grade 30k miles warranty) tires. Heck you never do rotation before 7,500 miles on most of the cars (old or new)
carrerascott
FUEL FTR
What do you mean repeated? Everyday driving with some spirited driving? Or repeated as on a bunch in a row so the tires get hot?
Our last car was an 08 porsche turbo cab. Tires lasted 12k easy...
carrerascott
FUEL FTR
I also would like to know if Tesla will pay for this. My Sig Performance has same wear pattern (with steel threads showing) at 9000 miles.
....... and the above is what it looks like after the inside shoulder is worn through.
Three comments come to mind. First, make sure there is zero toe in the rear.
Second, decide if you want to change the camber or run the car exactly as Tesla designed it. If you want to run less camber, you will need new upper links.
Third, if you choose to run the car exactly as Tesla designed it you will need to track inside shoulder wear and get comfortable with dismounting and remounting the rear tires so you can swap them right to left on the back of the car and run the old inside shoulder on the outside. This will require you to get comfortable running tires with the "outside" label on the inside of the tire as installed (see Jerry's comments). I normally do it with 33% tread remaining on the inside shoulder which normally ends up allowing me to use the whole tire.
I guess a forth comment would be that you can live with what you have but then I figured that was obvious and, judging by your post, unacceptable.
Three comments come to mind. First, make sure there is zero toe in the rear.
Second, decide if you want to change the camber or run the car exactly as Tesla designed it. If you want to run less camber, you will need new upper links.
Third, if you choose to run the car exactly as Tesla designed it you will need to track inside shoulder wear and get comfortable with dismounting and remounting the rear tires so you can swap them right to left on the back of the car and run the old inside shoulder on the outside. This will require you to get comfortable running tires with the "outside" label on the inside of the tire as installed (see Jerry's comments). I normally do it with 33% tread remaining on the inside shoulder which normally ends up allowing me to use the whole tire.
I guess a forth comment would be that you can live with what you have but then I figured that was obvious and, judging by your post, unacceptable.
1. Although camber is considered a non-wearing alignment angle, it amplifies any other misalignment.
2. The lower the profile of tire, the less able the sidewalls are to absorb alignment variances. Unfortunately, style has overtaken practicality with the move to lower and lower profile tires. (If the Model S could take 80% aspect ratio tires, that is what I would be running.)
3. Rapid acceleration increases the amount of negative camber. This effect might be reduced in the Performance+ -- anybody know?
4. The hotter the tires get the faster they will wear so repeated accelerations in a row will definitely accelerate this kind of wear.
There has also been some discussion about FMVSS 126 causing the manufacturers to increase the amount of negative camber. However, my reading of FMVSS 126 shows that it's about electronic vehicle stability control which shouldn't require a camber change in an of itself, although it might be easier/cheaper to implement a system that passes by adding additional negative camber. I don't pretend to be an expert on the FMVSS regulations, so there may be some part that I missed. In any case, FMVSS 126 has a lead-in time up to 2012 in some cases, so it's reasonable to assume your 2008 didn't have to comply with the same regulations.
FWIW, my 19" tires are very even all the way across at 6,600 miles.
steve841
Active Member
Jerry,
Camber may be a non-wearing angle but common sense would seem to indicate that, if you are not loading the outside edge due to high camber and low compliance, you will tend to wear the remaining portion of the tire.
My comments about FMVSS 126 were directed specifically at the emergency maneuver test where a steering machine is used to yank the wheel back and forth. Differential braking and other stability control tricks can do wonders for controlling certain issues (throttle lift on entry comes to mind) but is useless when you start talking about winding up a 4700 lb pendulum. You go about getting MS to wag its rear and it is going to take a bunch of camber in the rear so the car has something to roll over onto (as in, more patch). I believe all Tesla, MB, BMW, Audi and the like are using this trick to keep the car from swapping ends.
Lastly, something is going on here as the informal tire survey shows people getting everything from 4000 to 15000 and more out of 21" tires. There does not seem to be a correlation between wear and driving styles, or at least none that jumps out at you. A wild guess on my part would be toe as this is the only thing that is adjustable in the rear. Regretfully, there is no easy way to gather data on toe v. wear as I can not imagine everyone is going to measure wear and have the rear toe and thrust angle checked just for a survey.
Camber may be a non-wearing angle but common sense would seem to indicate that, if you are not loading the outside edge due to high camber and low compliance, you will tend to wear the remaining portion of the tire.
My comments about FMVSS 126 were directed specifically at the emergency maneuver test where a steering machine is used to yank the wheel back and forth. Differential braking and other stability control tricks can do wonders for controlling certain issues (throttle lift on entry comes to mind) but is useless when you start talking about winding up a 4700 lb pendulum. You go about getting MS to wag its rear and it is going to take a bunch of camber in the rear so the car has something to roll over onto (as in, more patch). I believe all Tesla, MB, BMW, Audi and the like are using this trick to keep the car from swapping ends.
Lastly, something is going on here as the informal tire survey shows people getting everything from 4000 to 15000 and more out of 21" tires. There does not seem to be a correlation between wear and driving styles, or at least none that jumps out at you. A wild guess on my part would be toe as this is the only thing that is adjustable in the rear. Regretfully, there is no easy way to gather data on toe v. wear as I can not imagine everyone is going to measure wear and have the rear toe and thrust angle checked just for a survey.
The Fury
Member
Tommy
Member
The Alignment Spec sheet lists the rear camber as -1.75 with a +/- 0.35 degree tolerance. That means a Model S would still be within spec with a rear camber as high as -2.10 or as low as -1.40. A 0.70 degree swing, that might well explain the variance in tire life that owners are reporting: some have negative camber near the top of the range while others near the lower end.
I am getting an alignment done so I know what my rear camber actually is. What I am hoping is Tesla offers, or at least sanctions the use of, different camber link lengths to permit those with very high negative camber to be able to get the camber closer to the "ideal" setting and extend tire life.
It's been posted that camber is considered a non-wearing alignment angle, and while in theory that may be true, it is hard to refute that excessive inside wear is taking place. The diagram showing a non compliant tire when set to -2.0 camber has full road surface contact on the inside tread but no contact with the road surface on it's outside tread has convinced me it's the high negative camber that is causing the inside tire tread to wear excessively.
I am getting an alignment done so I know what my rear camber actually is. What I am hoping is Tesla offers, or at least sanctions the use of, different camber link lengths to permit those with very high negative camber to be able to get the camber closer to the "ideal" setting and extend tire life.
It's been posted that camber is considered a non-wearing alignment angle, and while in theory that may be true, it is hard to refute that excessive inside wear is taking place. The diagram showing a non compliant tire when set to -2.0 camber has full road surface contact on the inside tread but no contact with the road surface on it's outside tread has convinced me it's the high negative camber that is causing the inside tire tread to wear excessively.
If there is any toe-out at all on the rear wheels, that combined with the stock camber settings will absolutely chew through rear tires.
Pretty interesting that some people are getting double the tire life of others.
Most cars ship with some toe-in on the rears which further increases stability - I don't recall what the stock specs are but having the toe set in as much as possible will at least help the tires wear more evenly, though you may see a slight hit in efficiency depending on where you start.
Pretty interesting that some people are getting double the tire life of others.
Most cars ship with some toe-in on the rears which further increases stability - I don't recall what the stock specs are but having the toe set in as much as possible will at least help the tires wear more evenly, though you may see a slight hit in efficiency depending on where you start.
this.
negative rear camber is intentional by Tesla. Therefore that wear pattern is expected.
It's not an alignment problem, it's the negative camber. and it's not a problem, it's intentional.
wow in such short miles you can worn out tire at this level. I know most of the $20k cars are install with bridgestone (lower grade 30k miles warranty) tires. Heck you never do rotation before 7,500 miles on most of the cars (old or new)
it's a low profile tire. even if camber was not negative, you'd still be replacing the low profile tires every 10k miles anyway because it's LOW PROFILE high performance summer tire. real shocker. if you don't want to replace your low profile summer performance tires every 5-10k miles, then don't get low profile high performance summer tires. get "regular normal people" tires.
yep.
hah, I am putting 4-5k miles on a month. Imagine if I had to replace my tires every month...that's like $15k/year in tire maintenance.
My 19's are wearing much slower than I expected (very good thing!). approx 8-9/32" at 13k miles. Not bad at all....should last me a good 60k miles before needing replacement. The 19" tires are not subject to the negative camber issues. Only the 21s are.
yea but it's not a tire defect at all. intentional negative camber by a car manufacturer won't trigger getting getting warranty applied by the tire's manufacturer.
doesn't sound like anyone's bothering to read them. lots of good info in there.
one of these days, the mods here should just gather up all my posts on how low profile summer performance tires are terrible for the average joe and daily commuting because the treads don't last very long (<10k), very unsafe in anything other than dry "summer" weather, and that they are very highly subject to blowouts and rim damage just due to their low profile nature and just compile them all into one post and make a sticky out of it so I don't have to keep repeating myself, lol.
It seems to me that focusing on camber is a mistake if you ignore toe. If your excessive wear is caused by toe, then the camber just focuses it on the insides of the tires - and even if the camber was "flat" you'd still have excessive wear - maybe not quite as much - just spread out and harder to see.
My non-expert theory is this: toe is the larger factor in excessive wear, negative camber would be much less of an issue if there was neutral toe.
Check your toe first, don't jump to blame the camber.
Thoughts from tire/alignment experts?
My non-expert theory is this: toe is the larger factor in excessive wear, negative camber would be much less of an issue if there was neutral toe.
Check your toe first, don't jump to blame the camber.
Thoughts from tire/alignment experts?
really summer tire last 10k or less (someone is racing on the road)
michelin tires (pilot sport ultra high performance) summer tire has 20k warranty and one of my friend got above 30k.
I am not sure what stock tires tesla install (maybe goodyear & they are pretty good too)... if tire last you less than 10k you do the math..
michelin tires (pilot sport ultra high performance) summer tire has 20k warranty and one of my friend got above 30k.
I am not sure what stock tires tesla install (maybe goodyear & they are pretty good too)... if tire last you less than 10k you do the math..
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