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WARNING!!! EXTREME WEAR ON REAR TIRES!

WARNING!!! EXTREME WEAR ON REAR TIRES!

I subscribe to the FB Tesla MS owners site and one post referred to extreme wear on the inside of his rear tires after only 8100 miles, the wear was so severe the cord was exposed. Being curious, I checked my rear tires and after ONLY 1600 miles I had the same extreme wear! I can see and feel the cord exposed. Everyone should check their rear tires IMMEDIATELY!

lolachampcar | 21 March, 2013

nhurst,
Tesla set the camber where it is on purpose and they offered no provisions for changing it (no adjustability) so I would not think they would offer a solution to something they do not see as a problem.

To be perfectly clear, I do not consider it a problem with the car. I consider it a design choice that I prefer to, and am comfortable with, changing.

nhurst | 21 March, 2013

lola - I understand. However my right rear is OUT of spec at -2.2 (the wrong direction in my judgment) and I would prefer to run about -0.8. I would appreciate any information you could share about your revised arms. (Drawings, availability, cost, installation difficulty, your experiences, etc. all would be appreciated.)

lolachampcar | 21 March, 2013

nhurst,
I did not want to point you or anyone away from the stuff I am looking at. I just wanted to make sure I was not seen as dinging Tesla, their engineers or the car.

It took me two hours today to (very slowly) install an adjustable arm and test my wireframe drawings and subsequent calculations. In short, I figured I needed 0.21" of added length to stand the tire up (decrease negative camber) by one degree. The drawing is referenced below and I've included a pic of the adjustable arm I used. The process also involved checking that there was sufficient toe adjustment in the stock suspension such that new toe links were not required. As it turns out, there is a lot of toe adjustment, more than sufficient to take out one and a half degrees of camber without new toe arms (on my car).

I have quotes from a machine shop to generate a set of longer arms. I need to put the final touches on the drawing so that there is sufficient material in the ends to allow for setting the bushing bore centerline anywhere from a 0.8 to 1.4 change. I'll then have a set made at 1 as a first test.

The links themselves will not be cheap. There is the basic cost of the aluminum part and then there is the bushing problem. Right now, my only option is to buy new links from Tesla and use those bushings (bushing cost of $220 per link or $440 for the set) or press the bushings out of the arms I pull off my car and use them. I'll likely take the second path but I suspect most anyone else will want to keep the original parts and will not want to exchange the originals for the longer units. I'm just guessing on that one.

Anyway, back to where I started this. I would think it would take two hours total to replace both links followed by an alignment.

The adjustable arm
http://www.lolachampcar.com/images/Tesla/Rear%20Suspension/Upper%20Arm.JPG

The every expensive cheap bushing
http://www.lolachampcar.com/images/Tesla/Rear%20Suspension/Bushing.JPG

My original wireframe drawing showing camber gain and required arm length to stand the tire up by one degree... It is simple but did the trick
http://www.lolachampcar.com/images/Tesla/Rear%20Geometry%20Model.pdf

lolachampcar | 21 March, 2013

if it will help, my e
mail
is
bill
at
lolachampcar
with a normal dot com at the end.
Bill

Bob Kroll | 22 March, 2013

I had less than 500 miles on my Model S when I had to replace the two right tires after going over some 3" beveled road separators at about 30 mph. The sidewalls were ruined and the front wheel cracked from driving about 1/4 mile to a safe place to stop. These tires, 21" Michelins, must be eggshells. Obviously, I shouldn't have driven over the separators which I failed to avoid when confronting them unexpectedly. But really, complete failure of two tires simultaneously?

lolachampcar | 4 April, 2013

New links in from the machine shop and off to be anodized.

http://www.lolachampcar.com/images/Tesla/New%20Upper%20Arms/new_upper_re...

lolachampcar | 5 April, 2013
jdb | 11 April, 2013

This appears to be false alarm site. Over 4,500 miles on my Sig performance with 21" wheels, not a light driver on pedal, took to service center today for other reasons, asked them to check tires, no tire wear problem at all.

lolachampcar | 11 April, 2013

jdb,
That is very good news. I was not so lucky and saw measurable wear within the first 800 miles (thus my panic).

I have a few hundred miles on my links now including some hard acceleration both in a straight line and side loaded with no change in stability. The car does seem to follow grooves in the road a bit more but I think that is a result of now having absolutely no toe front or rear.

RedShift | 11 April, 2013

Lola, amazing that you did all that. I hope it all works out well for you regarding wear and tear. Do these mods affect your warranty in anyway? Hope you are safe there.

djm12 | 12 April, 2013

Doesn't Tesla service includes unlimited free alignments and rotations? If so, I'll be taking mine in every 3000-5000 miles for a professional inspection.

lolachampcar | 12 April, 2013

RedShift,
I added just a touch of material everywhere on the link to stay on the safe side of Tesla's design. That being said, I think Tesla WAY over designed MS. If I were to guess, I would say the engineering team knew they had one bite at the apple and could not afford any issues. They responded by increasing the margin of safety in just about every part of the suspension. It is kinda nice for us MS owners :)

With respect to warranty, Tesla is obviously not responsible for my links. Apart from the link, everything else is Tesla down to the bushings that I pressed out of the Tesla links and into mine. In my situation, I balanced $1040 a set rear tires against the cost of the arms and the fact that the arms would not be in warranty. The arms won.

lolachampcar | 12 April, 2013

It is very strange that people's experiences are so varied. My (educated from other cars) guess is that the -1.9 degrees of camber on the rear of my car would wear out the complete set in about 8K miles and that includes moving them from left to right to use both shoulders. That whole process is a PITA and I can not imagine Tesla would install the tires with the "this side out" marking on the inside. Given this, Tesla's service would be of little to no use for this task.

JPPTM | 12 April, 2013

lolachampcar...many thanks for all of your efforts on our (and your) behalf. If I can summarize, for us 'average' MS drivers without extra driver training (to overcome natural urges in cornering), I assume the current factory design/setup allows for good handling and safety at the expense of potential greater tire wear, especially on 21" vs 19". If I do not drive like a maniac, watch my tire presures, and rotate every 5000 mi, I assume that I will get 'appropriate' tire wear. You have personally taken the route of improved tire wear as an expert driver with the training and expertise to manage the car far more skillfully than I.

lolachampcar | 12 April, 2013

JPPTM,
Everyone makes their own call but I really can not feel any significant difference in my car's handling. MS owners in S. Florida are welcome to drive it and judge for themselves.

I did the same thing on my Maranello (it had adjustable rear camber) and, likewise, could not tell any real difference in handling. Maybe you could tell the difference when pushed hard on a racetrack but I can not imagine I'll ever do that with my daily driver (MS).

carlk | 12 April, 2013

Lola, Seems you went through all the trouble to make the modifications because you assumed the car is designed this way and it's not a QC problem. Why is it that many people don't see the same wear as you did? Maybe you should let Tesla engineers to take a look at this first even though it appears you are very knowledgeable in this area. After all they designed the car. It's better for them to resolve any issues instead of second guessing it. That will also better serve other MS owners instead creating an uncertainty. Just my humble opinion.

RonaldA | 12 April, 2013

The roadster goes throuh rear tires every 6-8k miles I've had mine for 3 years and have replaced rear tires every year, and yes, I like to drive fast :-)

lolachampcar | 12 April, 2013

I started by asking Tesla for the alignment specs and my car was within those specs (thus my conclusion that, like BMW, MB, Audi and others, Tesla did it on purpose). In addition, the upper and lower links are a fixed length and thus I concluded it was not a QC problem and thus not Tesla's problem. Had I asked Tesla's engineers they would rightly have said we designed it that way.

I did not start this thread; mferrazano did. I too am perplexed as to why some people are having problems while others are not. My actions were not based on others having problems but from my own experience with other cars. I knew the second I saw the rear tires that I would have to do something. Once I saw there was no adjustment, I knew I had to make links. I've always been a little outside the box on these types of things and am in no way suggesting everyone needs to go out and replace their arms.

My guess is that the amount of toe the car has (within Tesla's spec) is being amplified by the camber. This literally is my guess and I have no data to back it up at all. Given that toe is the only thing that is adjustable in the rear it just shouts out to me as a potential player in the wear equation.

lolachampcar | 12 April, 2013

RonaldA,
Is that not what the Roadster is for???? :)

carlk | 12 April, 2013

Lola, Op did go to Tesla service and found out that alignment is way out of spec. That seems to be a QC problem to me. Aside from that I have not read anyone here say he/she had the problem and/or went to Tesla to get their opinions of what has happened. I don't think it's productive to second guess without words from horse's mouth and create uncertainties in MS owner's mind. Again I'm not an expert in this area what I am suggesting is just a logical thing to do. Tire wear like you described under normal driving condition is not acceptable even for a high performance tire, not to mention the ones on MS is not exactly that high performance. I'm sure Tesla will address it if you just discuss the situation with them.

lolachampcar | 12 April, 2013

Ok, for anyone reading, I am not suggesting there is a problem with MS.

As for you, carlk, back (and piss) off.

Bill

carlk | 12 April, 2013

Hey no need to get mad. All I'm saying is there is no evidence, and not very reasonable to believe, Tesla designed the car to have extremely high tire wear for a normal driver. Besides it is Tesla's responsibility to tackle the problem even if it is. No?

lolachampcar | 13 April, 2013

It's not mad, it is just past experience with forums. People do not act the same on forums as they do in person so I tend to push back quickly on forums.

I did not start this thread and I have gone out of my way to say it is not a design flaw with MS. A lot of manufacturers do the exact same thing and have accelerated wear as well. If you have an issue with the alarmist nature of this thread then I suggest you take it up with the originator and not me.

I have also questioned the wide disparity in reports of wear. It was a personal choice to make a change and I shared that information for those interested in the path I took. It is but one of many options when thinking about the issue (if there is an issue at all) and exactly the type and nature of information I hope to find throughly discussed in forums.

Brian H | 13 April, 2013

lola;
quite helpful for those who don't want to venture into the bushings unarmed. :)

rwang | 18 May, 2013

This is a great forum on the tire alignment issues at hand. I got 9000k on the back tires for a 19" P85 and for 400 rated tires, this is not right. Alignment appears to be the issue.

R

rwang | 18 May, 2013

Found out from America's Tire that they have seen quite a few Rear Passenger tires wearing out more than usual. This may be a known problem. 19" Model S.

rwang | 18 May, 2013

Okay confirmed w/ a few other owners that this is a known problem for early owners pre 5000. Maybe they'll take care of us.

TikiMan | 18 May, 2013

I am Sig 736, nearing 10k miles, and not noticing that much excessive wear on my rear tires.

I wonder if it has something to do with the type of roads, driving style, and or adjustments Tesla made to the toe on MS's after my vin?

DouglasR | 18 May, 2013

It probably makes sense for those of us with early production cars to ask service to check the tires and alignment whenever we bring it in for a repair, upgrade, regular service, etc. And of course to check the tires ourselves, and bring the car in if the wear looks excessive.

rwang | 18 May, 2013

DouglasR

good point. I think those before 5000 should probably take a look at their tires and see if they are getting uneven wear as well.

Maybe this will get standardized in their service knowledge base (if they have one)

wheatcraft | 19 May, 2013

Just to add another point to the graph: I have VIN 62XX, picked up on March 6. I now have 4,000 miles, and I can see no discernible wear on any of the tires.

wheatcraft | 19 May, 2013

Oh, sorry, mine is a P85, 19" tires.

mark_g | 19 May, 2013

I was the original poster. TM replaced the two rear tires free of charge, re-aligned the car, and with 4000+ miles on them so far so good, the tires look fine. It was the alignment being so far out of spec that ruined the first set of rear tires.

rwang | 19 May, 2013

mferrazano

thanks. I'll reach out to them and figure out what's going on.

R

John38 | 2 June, 2013

We have a Model S. I did not notice that our 21" tires were wearing on the far inside. At 9596 miles I got a warning indicator of low air pressure so I stopped to check the tires. I found the wear was so bad it had wore all the way through the tire and the air escaped. Got the car towed home. Called Tesla Service center and they said this is normal. Paying $0.15/mile for just tires seems crazy! I am thinking about replacing the 21" performace wheels with the standard 19" wheels or some other wheel . . . any suggestions?

jat | 2 June, 2013

@John38 - friends with sticky performance tires on performance vehicles get similar mileage, so that is one of the reasons I went with 19" wheels. I have 5600 miles on mine, and before yesterday didn't have any noticeable wear at all -- after some hard laps at the track, the outside edges are noticeably worn a bit, but nothing excessive.

nickjhowe | 2 June, 2013

@John38 - if you haven't been doing burnouts, and the tire wear is very non-uniform (heavy wear on the inside) then based on other threads this is almost certainly a camber issue. Less than 10,000 miles is NOT normal. There are documented cases on this forum of people with minimal wear levels at their first service.

If you are not getting any joy from your local service I'd escalate up the service chain. They need to check the camber angle.

CAdreamin | 2 June, 2013

Aside from alignment, the MS really needs 9.5" wide rims in the rear with 255 or 265 wide tires to better handle all that torque and weight IMO. 8.5 front 9.5 rear

lolachampcar | 2 June, 2013

MS uses over 2 degrees of negative camber and, apart from "bolt slop" it is not adjustable. I have found that anything near negative two will fry the inside shoulder of low profile tires in short order.

Following up with the low profile comment above, the larger rears should wear the inside shoulder faster.

The only solution I have found (apart from putting large sidewall tires on the car ala 19"s) is to fabricate arms to reduce camber. Mine now has about minus one (almost matching the fronts).

ajamison | 2 June, 2013

as someone who is considering this car i read this thread in hopes of learning about a potential issue then became interested in what Lola was doing with the whole customer stuff. Once I looked at the thread you have made on TMC I realize I know nothing about cars as I understand absolutely nothing about what you talking about.

So can someone sum the findings about the tire issues in this thread up for me in non-gearhead language? I have no idea what a Camber is or how those numbers have any impact on anything.

ajamison | 2 June, 2013

customer in line two of the post above should have been custom

Dr. Bob Reinke | 2 June, 2013

I have not noticed excessive wear on my rear tires; however, I am curious if others have experienced what I call, "busy stearing." Perhaps I am very spoiled, my previous cars have all been Toyota Supras I have compaired the necessity and frequency of correcting the direction of the Tesla on a streight road. The Supra would require less than one or two movements per minute (mile)while my Model S requires no less than 50-60 per minute (mile) covering the same surface. Frankly, driving requires constant and undisturbed attention--even to the point of exhaustion. Twice it has been in to the service center for alignment check and inspection for something loose. The last time they found that to camber on one side in the rear had fallen. A friend with an alignment shop has driven our Tesla and he believes the problem is an over active camber change from verticle movement of the rear suspension. Do others have similar overactive steering?

nickjhowe | 2 June, 2013

There are a couple of sections of highway where my S wanders. But it only does it there. In my case I believe it is tramlining, and not the loose suspension issues that a couple of others have reported.

TikiMan | 2 June, 2013

I had my 21 all season tires rotated yesterday @10,700 miles. My rear inside tread had a bit more wear than my fronts, however, the tech said I should get at least another 5k to 7k miles out of my current tires.

Regardless, I can see that the camber (toe) is wearing the inside rears more than the fronts, which is common on performance cars to achieve better cornering.

The tech did say that he has seen many 21's that needed replacing at less than 7k miles, however, when you do a good deal of fast cornering, excessive tire wear is fairly common. I don't do much fast cornering where I live, so I suspect that's why mine have lasted so long.

I will be interesting to find out how quick P85+ tires go.

CAdreamin | 2 June, 2013

Thanks CnJs for the post!

nhurst | 2 June, 2013

Camber and toe are two different, though related, parameters.

lolachampcar | 3 June, 2013

First let me start by saying one, I am not a production car suspension designer/engineer of the type employed by Tesla. I am speaking only from practical experience. Second, all major manufacturers are doing the same things as Tesla on the rear suspension including MB, BMW and Audi. This is not a MS specific topic (high rear camber).

I apologize for the tech terms. I'd intended my threads for car nerds and had not considered those simply looking to evaluate MS. For those not familiar with suspension terms the first thing to remember is the first paragraph. All manufacturers do this as anyone that has owned a BMW with low profile sidewall tires can attest.

Camber is the tilt of the top of the wheel towards the center of the car. If you sit ten feet behind a MS with 21" wheels you can look at the wheels/tires and see how they are canted inwards at the top. That is called negative camber and the specification for MS is around two degrees of negative camber in the rear of the car. Now exaggerate that tilt in your mind and you can visualize how the tilt (camber) puts more pressure on the inside of the tire where it hits the ground. This is why the inside shoulder wears more than the outside.

The simple explanation for why manufacturers put this amount of negative camber in the rear requires a little more visualization. Think of yourself as a very strong person when you are standing behind MS and use your finger to push the back of the car to one side. Try to visualize the tire on the other side of where you are pushing. As you push, that tire will "roll" more flat the more you push the car. This is the exact same thing that is happening when you whip the steering wheel one direction and get the back of the car swinging around. The camber helps put more tire on the road when the back of the car wants to pass you.

I hope the above helps and welcome any help here :)

Again, MS is doing exactly what everyone else is doing.

There does seem to be a very large disparity in owner's experiences. The 19"s seem to wear much less which may be related to the large side wall of the tire. My experience is only with short side wall performance tires so I have no reference points for comparison. I'll drop a note to Tesla and see if I can get their suspension engineers to explain the vast differences in wear.

Dr. Bob,
I too find my P85 does what I describe as hunting. It tends to follow little grooves or other anomalies in the pavement at highway speeds. I've chalked this up to very near zero toe front and rear. For those not familiar with toe, it is the direction a pair of wheels point with respect to each other. Toe in (most common) is when a set of wheels point inwards (WRT the direction of travel), zero toe is when they point straight ahead and toe out being when they point outwards (not normal for street cars but sometimes used on race cars to improve turn in). I believe Tesla has specified near zero toe to decrease rolling resistance and thus increase range.

I have not played with toe on street cars in a back to back fashion but have many times on race cars. One example is a "normal" set up for a road course where toe is used to help the car turn. The car is very stable in a straight line. I've run the very same car two weekends later at Daytona where drag reduction and straight line speed are at a premium and thus we run zero toe (and less rear camber). The very same incredibly stable car want to follow every little imperfection on the banking. You simply learn to loosen your grip on the wheel and "let'r eat" as the southern boys say. The car just hunts around a little bit.

With respect to camber chaining with wheel position, I took a close look at "camber gain" when I did my suspension links. It is relatively small. Here is the somewhat cryptic line drawing I did to determine how long the new links needed to be to put the rear camber where I wanted it. It also depicts camber gain for the car going from standard to low ride height (what it does when you are driving down the highway). I figured there was 0.4 degrees of camber gain when the car drops 2". So, if you had -2.0 degrees of camber at Standard ride height, you would have -2.4 degrees at 70 mph. That seemed perfectly reasonable to me and in line with the active air suspension which allows for significant changes in ride height (so camber must remain reasonably stable as the car must be drivable at different heights). The lengths and placements of the upper and lower suspension links would indicate low camber gain as well.

http://www.lolachampcar.com/images/Tesla/Rear%20Geometry%20Model.pdf

lolachampcar | 3 June, 2013

.... With respect to camber CHANGING with wheel position....

nickjhowe | 3 June, 2013

@lolachampcar - as you've done your investigations have you come across anything that would explain the absurd levels of wear that a couple of owners have seen on rear tires (eating through to the carcass in <5000 miles)

lolachampcar | 3 June, 2013

I just sent an email to Tesla engineering on that very point. A couple of owners have reported that the service center found an issue with the rear alignment an comp'd the tires.

The only thing that is adjustable in the rear (not counting ride height) is toe and, if that was out or the adjusters were loose - big IF and only speculation, it would cause high wear rates with the negative camber causing most all the wear to be on the inside shoulder. The issue would surely have driven high WHr/mile values as well which should have returned to more reasonable numbers after the toe correction.

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