Negative Camber in the Rear and Expensive Tires

[lolachampcar]

pics of the upper camber link
http://www.lolachampcar.com/images/Tesla/tesla_model_s_rear_suspension_ge.htm

and a quick line drawing showing lengthening of the camber link to take out one degree and camber gain for 2" of travel
http://www.lolachampcar.com/images/Tesla/Rear%20Geometry%20Model.pdf

 

[rogbmw]

Sorry...I see how I mis-read the information. I was trying to read a "the" into the sentence - like this: Tesla has fixed "the" rear camber.

 

[lolachampcar]

Originally Posted by lolachampcarandystj,
. . .Do you mind if I repost your comments here?
http://www.teslamotorsclub.com/showt...xpensive-Tires
By all means. Great discussion over there, and I'll be looking at that thread as it develops. Prior to reading that thread, I did not even have a working knowledge of "camber," but I do remember noticing and pointing out the rear tire angles.

I did not even think to get a measurement of the tread across the tire, but inside was competely bald and I did not even notice it 'til the road noise and driving dynamics screamed at me. The outside was pretty warn, but not down to the treadwear indicator. Mid tire was basically at the indicator. Mileage was right at 5,500 when I got into the shop, but it was perhaps 100 miles after the road noise became noticeable. I do look at the tires semi-regularly, but I always just glance at them while plugging in. Accordingly, I was just looking at the outer tread. That was a mistake, as I was getting pretty close to blow-out range when the noise turned up.

Andy

 

[Shakespear]

What I am to understand my tesla EV has no camber adjustment and I will have to replace rear tires every 5k to 6k.
Is there a solution ??

 

[Kaivball]

What I am to understand my tesla EV has no camber adjustment and I will have to replace rear tires every 5k to 6k.
Is there a solution ??

Only if you drive like a maniac and every launch is a 0-60 competition.

Yes, under those circumstances you will have to replace rear tires every 5-6k miles.

The solution: drive it more like your previous car.

Any high performance car (0-60 in less than 5 seconds) will eat rear tires like crazy when you constantly induce launch grins.

 

[dflye]

My 21" came with Continentals, had them look at the tires when I had a bit over 6k miles on the odometer, wear at that point was getting pretty bad on the inside of the rear tires.

Had the tires rotated at the service center last week, longest time spent during the process was sorting out the amount to charge with their new service SW, doh.

After inspecting the tires, he is estimating that with the rotation to get some fresher tread on the rear tires they should last until the "annual" service at 12.5k miles, which at the rate I'm going I'll hit by June. Thinking they are needing either a high-mileage pre-purchase service plan, or some clarification on the plan names, as the "4 year plan" is looking like it'll last me 2 years!

I don't encounter enough cars that can make 0-60 launching a competition, so while I haven't been rocketing away from a stop as much as when I first got the vehicle in November, I'm not exactly a light-footed driver. Obviously, YMMV applies when it comes to tread life. :wink:

 

[Kaivball]

Well, 12k for a high performance tire is already better than the referenced 5-6k...

 

[lolachampcar]

I think there are two things at play here. The first is lead foot tire degradation. This is a cost for playing that I accept with a big grin.

The second issue is the manufacturer purposefully putting a large amount of negative camber in the rear suspension to add a margin of safety for the owner. The increased safety comes in improved throttle off over steer (too fast into a corner and jumping off the throttle). This is common on high performance European cars (BMW, Ferrari, etc.). Some cars have fixed rear camber settings.

My MSP85 has -1.9 degrees of camber in the rear. It is my experience that this will shred the inside shoulder of the rear tire in short order. Short order is tire dependent but I use 1/2 the available tire wear as a rule of thumb. The tire would literally last twice as long if allowed to run more "square" to the ground and use all of the contact patch.

I've started a process I have followed before by ordering the upper link from Tesla, using the upper link to build two temporary adjustable upper links, use the adjustable links to set something less than -1 degree of camber then check that I can adjust toe within manufacturer's specifications. On occasion, there is not enough toe adjustment and I have to make both custom toe and upper links to achieve the goal.

With Respect to Tesla's Design-
This is not a manufacturing or design flaw. Tesla chose this path as have other manufacturers. It is my decision to decrease safety margin for improved tire degradation. I am comfortable with high performance cars with less rear camber. So, please read this thread as an enthusiast's project and not negative towards Tesla or MS as that could not be farther from the truth.

Lastly, yes you can rotate the tires front to back and postpone buying tires. However, when all is said and done you will be buying $2k worth of tires instead of $1k when there is no more tread on the inside shoulder.

 

[WarpedOne]

lolachampcar, thumbs up for a great write-up on the issue.

 

[jkirkebo]

Lastly, yes you can rotate the tires front to back and postpone buying tires. However, when all is said and done you will be buying $2k worth of tires instead of $1k when there is no more tread on the inside shoulder.

Can you swap the tires on the rear rims, so the left tire ends up on the right rim ? This way the inside shoulder would now be the outside shoulder and the tire still rotates in the same direction.

Or do the tires have a "this side out" or equivalent marking ?

 

[dflye]

Can you swap the tires on the rear rims, so the left tire ends up on the right rim ? This way the inside shoulder would now be the outside shoulder and the tire still rotates in the same direction.

Or do the tires have a "this side out" or equivalent marking ?

When I asked the Tesla service technician, he indicated that there was an inside vs outside orientation to the tires, so not possible to simply swap the rear tires to attempt to equally wear down the inner/outer edge of all four tires. Appears that best one could do is end up with 4 tires where the inside tread front and back wears out at the same time with a single rotation about half way through their expected life.

 

[Johan]

Hmm... I've never been asked when buying tires if I want left or right oriented tires - which would be the case if there was a given inside/outside with a fixed direction of orientation.

 

[dflye]

Hmm... I've never been asked when buying tires if I want left or right oriented tires - which would be the case if there was a given inside/outside with a fixed direction of orientation.

Yeah, I was a bit confused as well, but then he mentioned that he normally swaps one pair left/right at the same time as front/back, meaning that they are actually rotating in the reverse direction. This is definitely the case, as I had curb rash on the front right tire, which is now on the left rear. So apparently they have an inside/outside orientation requirement but not a rotational direction requirement.

 

[lolachampcar]

Yes, the tires are unidirectional and, in my experience, yes you can move them across the car. The second yes obviously goes against the markings on the tires but I have never had a problem doing it. I can not imagine Tesla ever condoning running the tires against mfg instructions.

The above being said, I have had problems in the past rotating radials in the opposite direction. I damaged a few and learned not to try it. There may be something different about the Pilots that allow this but I would be cautious trying on my car.

 

[andystj]

Only if you drive like a maniac and every launch is a 0-60 competition.

I think you just said I drive like a maniac. Ouch. At least I'm smiling.

A quick follow-up by the maniac. After the shock of unwittingly shredding my first ever set of summer tires in 5,500 miles and two months, I opted to switch over to 19's and all-season radials. As it turns out, someone around these parts ordered 21" grey wheels during the end-of-year bottleneck. His car was delivered with 19" wheels and his grey 21"'s followed 6 weeks later. Tesla made me a deal on the slightly used, but perfectly clean 19" wheels with TPM's and OEM tires. They had just over 1,000 miles on them, and no discernible wear (even, uneven or otherwise).

I REALLY miss the grip the contis gave me, but they take the edge off the maniac in me, and the car really does still get up and go.

I'll reload the 21"s soon, but for now I'm testing out the traction control dynamics.

Andy

 

[yobigd20]

What I am to understand my tesla EV has no camber adjustment and I will have to replace rear tires every 5k to 6k.
Is there a solution ??

Yes. Get rid of the 21" summer performance tires and put 19s on. You bought yourself into this when you put the 21s on. They are not meant for good tread wear and long range. I preemptively downgraded from free 21s to 19s when I finalized exactly for this reason. Any cost savings you get from buying the model S and not paying for gas are diminished, if not even WORSE, by the maintenance cost of those 21s (you may even pay more per year because you need new tires every 6 months). If you think you are "saving money by not paying for gas and helping the environment out by driving an EV", here is your wake up call: YOU ARE NOT as long as you keep driving on those 21s.

 

[lolachampcar]

Gas? Environment? What is yobigd20 talking about? I bought MS because it is an outstanding car. Is it really electric and good for the environment?

All kidding aside, performance tires do wear quickly. My concern with this thread is confirming that the inside is wearing too quickly (which I think we are on our way to doing) and developing a solution for using the whole contact patch thus improving the limited life of the tires.

 

[strider]

The Conti's are "only" $293 each at tirerack so less painful than the Pilots when they wear out. Hankook also makes a 21" fitment for $185.

 

[lolachampcar]

I normally move to Nitto but I am a bit torn here. My impressions, although not back to back, of the Contis was not so good. I was more than pleasantly surprised when I drove home on the Pilots as the car felt much better than either of the Conti shod cars I drove.

 

[Kaivball]

I normally move to Nitto but I am a bit torn here. My impressions, although not back to back, of the Contis was not so good. I was more than pleasantly surprised when I drove home on the Pilots as the car felt much better than either of the Conti shod cars I drove.

I am running the Contis on my BMW 650 and tread wear and handling has been outstanding, IMHO. Previous tire was Michelin Pilot Sport. I wore those out in 11k miles. The Contis are at 15k and counting.