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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!

Are these 19s or 21s? I have 2000 miles on my 19s, and there is no discernible wear (there are even rubber "tags" still on the inside edge of the tire), and I have not been shy with using the accelerator.

The extreme performance tires, such as the 21s, are much stickier and therefore they wear much faster. In addition to not being suitable for winter use, that is one of the reasons I didn't want 21s even if I liked the look better.

I have 21 tires....these tires have not been abused....but after 1600 miles? This can be a real problem, the ONLY reason I checked was due to the post on the FB site. Who checks for tire wear on a new car after only 1600 miles, especially so severe that the cord is showing.

Just checked my 19" tires, 1550 miles, and I can't see any wear at all on any of the tires. Seems your problem might be an alignment issue, although I didn't think the rears have an alignment. You should definitely have service look at it.

Early wear on tires can be a sign of misalignment which is not uncommon on new cars. My previous car had this exact problem. I went through a set of front tires in like 3 months. When I had them replaced the shop said the alignment was way out of whack.

I have no experience with the sticky tires on a Model S, but friends I know that have them on other high-performance vehicles reported getting 5-8k miles on rears and 10-15k on the front tires (and they are much more expensive than the all-season higher-profile tires as well).

When I had an MR2 Turbo, which is midengine with 2/3 of the weight on the rear, I would go through all-season rear tires in 15-20k miles -- I can only imagine how quickly I would have worn out extreme performance tires.

I agree, 1600mi seems excessive -- if you haven't been driving hard, then you might want to get the alignment checked (particularly camber if it is the inside edge).

The tires look like the camber is so far off that I am riding on about 2 inches of rear tire which would explain some of the ride issues I am having (P85)....I just spoke with TS in Fremont I have an appt on Monday, lets see what happens. No matter what tire, everyone should check. I took delivery on Dec 30.

Just checked, left rear only slightly over-worn on the inside, compared to outside. Right rear and fronts seem fine. Only 1500 miles though...

I'll be coming up on 4k miles soon and no unusual wear on my tires. P85-21" As far as them being 'sticky' or aggressive, the tread wear rating is 340, which is on par with any high performance tire and you should see lots of miles, like 15-20k out of them. The only thing that is going to be hard on these tires is the sheer weight of the car. At 4700 split almost 50/50, those rear tires have to support around 2300lbs! The torque they have to endure is amazing too! My diesel truck wears rears faster than the front, even though the load is much more in the front, but due to the torque put through them any time I have to make that beast accelerate, it just shreds them.
Me and rear tires don't have the best relationship...

Nkyta: bring your car into TS immediately and have them check your alignment especially the camber

I have 5k miles on my P85 w/ 21's, and don't see any excessive wear on the inside rear tires.

Being the tire grooves don't match on each side, it's difficult to tell how much extra wear is on the outside groove verses the inside groove (using a depth gauge).

I use to own an early first year 2003 Nissan 350Z, and Nissan deliberately ‘toed-in’ the camber on the front and rear wheels (like a race car), so early owners would brag about how amazing the car cornered (it did in-fact corner really well). Eventually I realized what Nissan had done to make it corner so well, and got them to replace all my tires due to it being deliberately ‘toed-in’ too much at the factory. Of course after they balanced the camber on my new tires, it no longer cornered as well (go figure).

The camber on my car is so bad that the tires are destroyed and must be replaced after only 1600 miles. This also explains the handling issues (I hope) I have been having, slight fish tailing on a simple turn, skittering all over a "damp" road..the list goes on..

Fish tailing and tire wear sounds more like a heavy foot issue then anything else to me......sure you are not spending too much time with the pedal to the metal? Toe-in usually means greater cornering.....

MS carries about -2 degrees of camber in the rear meaning that the top of the tire tilts inward at a 2 degree angle. This results in most of the load being carried by the inside shoulder of the tire. This is not uncommon for BMW, Porsche and the like; nor is wearing down to the cord on the inside of those cars in very little time. Here are some numbers from my car at 800 miles-
http://www.lolachampcar.com/images/Tesla/Rear%20Suspension/rear_suspensi...

Tesla built the upper and lower control arms on the rear suspension with no adjustment. Negative camber is used by manufacturers to control throttle off over steer and Tesla did this on purpose. It is to save people from having the back end come around if they got scared entering a corner too fast and jumping off the throttle. I purchased an upper control arm and have been working on a modification that will bring the rear to something at or just under one degree of negative camber. This will place the load across more of the contact patch and extend tire life. I’ve had to do this on both BMWs and Ferraris in the past. In addition, I’m generating the tools necessary to quickly asses the alignment as I make changes. This is needed to do things like verify toe after the camber change. MS’ rear toe is adjustable but probably not enough adjustment exists to accommodate the camber change. It may be necessary to modify the toe links as well. Here is my working page-
http://www.lolachampcar.com/images/Tesla/Alignment/tesla_alignment.htm

I've asked owners for feedback and it would seem the 19s are best for wear with the Continentals being second and the 21" Pilots being the worst. I've got the pilots so, at over $1K per set, I am highly motivated to find a solution that works for me. It is worth noting that I am perfectly comfortable with less negative camber in the rear of a car. I’ve made these changes to other cars I have owned (and still own) but that does not make it right for other drivers. I always ask “why did the manufacturer do this” before I make any changes as there is almost always a good reason for things being as they are.

About the lead foot thing-
MS is a very heavy car and torque is readily available. It would not surprise me if rear tire wear is high even without full on launches on a regular basis.

4000 miles - checked all 4 tires after seeing this thread. No abnormal wear on any of the tires.

Also watch out for inflation problems. Under-inflation causes dramatic edge-wear.

Just a shout out to lolachampcar for his expertise and efforts on behalf of all of us. If I understand correctly, Tesla made a deliberate engineering decision on the rear camber to benefit all of us 'non-professional' drivers, and it will more heavily affect those with the 21" wheels. Can I assume that proper front-rear tire rotation while help spread the wear a bit?

Proper rotation' as well as proper inflation, are two of the best things us "amateur" racers can do to extend tread life.

That's my take on the rear suspension based on past experience but not based on any conversations with Tesla engineers. If anyone has any information please chime in here as I wish we had a bit more insight into Tesla's thinking.

@lolachampcar - I don't -2 degrees is a lot on a performance car -- my Camry Hybrid had -1 degree on the rear, and it was far from a performance vehicle.

My MR2 had a lot of negative camber on the rear (don't remember exactly), and it was the inside edge that wore quickly as expected.

Its tough to know all the angles on a multi link like the S has. Being a typical SLA setup, it should have some camber gain as it sweeps upward, but how much. And on that note, since the car lowers itself at speed, I could see S's with more highway miles exaggerating this effect. I did read somewhere that driving the S at the limit is easier when suspension is put in Low mode...
The thing that strikes me odd, is like lola said, it has fixed links everywhere. For the most part, camber should remain pretty equal car to car. I'd have to see if there are some sort of eccentrics used for adjustment.
Ohh, look I have a can of worms! Anybody care to open it?

torst1: I appreciate your arm chair analysis however I just got back from the Tesla SC in Fremont. The tires were so bad that one actually deflated in a parking lot and I had the car towed to Fremont. BOTH rear tires were so severely damaged that both were junked. The guys at the SC were great, Andy, Kyle, Eric spent a good part of their Sat nite replacing the tires and aligning the car. BTW the car was totally out of alignment on all four wheels to a degree not seen before. When I saw the tires off the car, the wear pattern was amazing. 80% of the rear tire tread was in pristine condition, the remaining 20% or less was worn down to the core. The tires were replaced under warranty. The now handles great. I repeat check your tires carefully, the damage on my tires was hidden since it was on the inside edge and could only be seen by getting on your hands and knees and looking under the car at the tires.

lolachampcar: the specs are as follows rear toe 0.2 to 0.6 degrees MY car came in at: rear toe -1.88 degrees, rear camber spec is -2.1 to -1.4 degrees my car was -1.1 degrees.

mferrazano,
Thanks for updating us with data. Excessive toe angle is the real tire-killer, as it causes the tread to "scrub" across the pavement. Were your tire treads feathered?

The stock numbers look optimal. Do you have the numbers for your front alignment, both stock and previous condition?

Kludge: Erik said he could hear my tires scuff across the floor of the SC when he was driving it over to the alignment station.

Front:
Camber -.2 spec is -1.1 to -.4
Caster 2.7 spec is 3.5 to 4.5
Toe .31 spec is -.15 to .05

Guys, thanks for this. I've checked my tires (reached under car each side with my iPhone and snapped some good flash pictures instead of crawling around with a flashlight). I don't see anything obviously wrong, but I have a good tire shop here...can I have them check these three alignment specs and go to Tesla if they are wrong or are these measurements unique to the Model S such that my tire guy won't be able to measure this way?

Jat,
I agree. Negative 2 is not out of line with other performance cars. I just personally can not put up with the tire wear associated with this setting and thus my personal concern.

CnJsSigP,
Tesla did a great job with camber gain. I've got a wire frame drawing of the suspension lowering from Standard to Low with .4 degrees of camber gain for 2" of lowering -
http://www.lolachampcar.com/images/Tesla/Rear%20Geometry%20Model.pdf
As you point out, this means that my MS has more like -2.5 degrees of camber at 60 mph rolling down the highway.

mferrazano,
Been there and done that with my rear tires on other cars. It was a painful lesson but now when I see that kind of negative camber in the rear I pull out my camber gauge and check it. If I find it high, I start the process of dialing it out.

Lastly, I've looked the rear suspension over reasonably well. I found toe adjusting eccentrics on the inside (if I remember correctly) of the toe links but all the upper and lower control arms are fixed. That being said, I've been know to be able to hide my own Easter Eggs so it would be good if someone else could verify this.

I'm current working on an adjustable insert to replace the stock rubber insert on the outside of the top link. I will then use this to verify my drawings of the rear geometry and confirm the exact amount I need to lengthen the upper arm to get me under my goal of less than one. Once I confirm the length, I'll make sure the eccentric on the toe link will allow me to get the toe right and proceed with a permanent change to the top link..... at least that is the plan as of today :)

Since this has turned into quite the interesting suspension thread, here is a link to a good read about the S suspension...

http://www.edmunds.com/car-reviews/track-tests/2012-tesla-model-s-signat...

Enjoy

@CnJsSigP,

Very good article, thanks for posting it.

@CnJsSigP

*thumbs up* 4 link


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