Tesla Model S

The current Model S is a Red/Black P85+

The Tesla Model S carries a lot of negative camber in the rear suspension in Standard ride height (over -2 degrees). If the car has air suspension, it will lower at highway speeds which further increases negative camber. Negative camber is associated with high rates of inside shoulder wear on tires. This page and related sub-pages describe the issue in more detail along with steps I have taken to address any issues.

By my estimate, it is far more dangerous to have tons of camber in the rear for oversteer margin than not.

Here is my thinking.

Lots of camber will save your bacon on that one occasion where you whip the wheel much harder than you really should have at speed to avoid something while simultaneously running out of talent to correct for the back stepping out. Like a police officer pulling his weapon, this will probably never happen to most but it is a real and valid concern.

Lots of camber will also wear the inside of the rear tires. There is sufficient evidence to suggest a wide disparity in the rear shoulder wear rate. Unless you are aware of the issue, you are not likely to routinely crawl around on the ground under the back of your car to check the wear on the inside shoulder. The results have already been seen. Several forum members have posted pictures of rears where they have gone though several layers of cord before identifying the problem. This tells me to a certainty that there will be a loss of pressure due to inside shoulder wear. If that occurs at speed, there will be a dramatic moment.

It is difficult to weight the two outcomes. MS has the camber so we can not judge the fleet's willingness to swap ends. My car does not have the camber so I am confident it is a non-issue (but then that is just me). By the same token, all cars have the camber thus we will see the tire wear.

For me, it comes down to "I know this will happen with a significant percentage of the fleet" versus "someone way out on the bell might have an issue". As a society I feel we have taken to focusing on the ends of the bell curve while loosing sight of the center.

For those interested in current (as of 2013) electronic stability control regulations, FMVSS 126 is a good read. Of particular interest is the over steer portion on II-5

I have had play cars in the past which I simply do not drive enough to make fundamental changes in an effort to fix camber. In these cases, I typically monitor tire wear and swap the tires across the back of the car when the inside shoulder gets to about 30% tread depth. Most of these tires are "directional" which means they typically have more rain grooves on the inside of the tire (see Pilot photo below). I figure that having one less groove with 80% tread depth is as good, if not better, than having an extra groove at 30%. This approach requires dismounting and remounting the tires each time which is why I chose to simply fix the camber issue on my daily driver (Model S).

Picked up the Red/Black P85+ today (July 20,2013). The following photo gallery has shots of the car and some selected pictures of installing the ball bear based upper arms in the rear. I've also included pre and post link alignment data (do not pay attention to the front values on the post data - rack issue). We had to loosen the sub frame in the rear to allow it to rotate to get correct toe on both sides of the car.

For those of you that got to this page without going through the root pages, About the Author-

Why I am comfortable with a little less over steer margin on my street car.

Why I do not ride bikes.

Why I like Champaign.

Lastly, for those not familiar with Tesla, Model S and what is going on, this is a good read.

Detailed pictures of the first Model S (Feb 13 delivery) as of May 16, 2013. This car has been sold.