Negative Camber in the Rear and Expensive Tires

[araxara]

low profile summer performance tires are terrible for the average joe and daily commuting because the treads don't last very long (<10k)

I have the 21" Continental tires and I do some commuting and mountainous highway driving. I have over 11Kmi with 7/32" tread left. The variation in 21" tire wear for various owners is too great to be attributed to some generic design flaw with the car or the use of performance tires. There is something specific going on with some cars, or possibly a bad batch of tires.

 

[Dave EV]

Thoughts from tire/alignment experts?

+1 especially considering the very wide range in wear that people are experiencing.

 

[lolachampcar]

I think Tommy and richkae are both right. I believe you can have increased wear with high negative camber and exacerbate the problem with toe.

I would make one observation and that is what Tesla calls the high end of their allowable toe adjustment in the rear probably just makes the minimum toe in for a M series BMW. MS does not run much toe when compared to high performance sedans.

 

[lolachampcar]

We really are going to need more aggressive investigation if we are going to learn the answer. My first vote is a rear camber and toe survey to add to the existing wear information but that is going to be a PITA for owners. You can get a good idea of camber simply using an IPhone but toe really needs an alignment rack.

 

[jerry33]

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.

Agreed. The camber will magnify any misalignment in other angles. You should be able to feel feathering from toe with the palm of your hand (never the fingers). The tires shouldn't feel different when moving your hand in and out across the tread of the tire. If it is smooth one way and rough the other, then there is feathering and toe requires adjustment. The problem you sometimes run into is that the alignment machines are not calibrated very well. If you can find a place that uses manual methods to check on the machines use that place.

 

[carrerascott]

Will try to get a hold of tesla service tomorrow. Really don't want to be stuck without the car because of this. I think 5500 miles indicates a problem imho, we've had Porsche Cayenne Turbos, Porsche 996 Turbos, Porsche GT3, all of which would get 10k at least out of the rear tires.

 

[lolachampcar]

put a set of lowering springs on that 996 and you'll see over 2 degrees of negative and 5000K out of the tires..... I just helped a buddy put GT3 lower arms on his for that very same problem.

 

[carrerascott]

Maybe but shouldn't a performance family sedan from the factory get more than 5k from its tires?

I imagine if this happens to CR on their long term road test, they won't be so forgiving.

 

[dsm363]

It may be a problem so getting it checked our is a good idea. They are performance tires so wouldn't be surprised if it was normal. Rotating the tires the way Jerry said will likely be the best bet if you decide to stick with performance tires.

 

[NigelM]

Mod Note: merged *carrerascott's* thread into this one as the discussion was in both places.

Maybe but shouldn't a performance family sedan from the factory get more than 5k from its tires?

Not necessarily, it depends on your driving style, the tires and the road surfaces. The Contis seem stickier than other "regular" tires and we zipped through a set of rears in 12k miles. My Roadster gets a (ahem) slightly more aggressive style of driving and each set of rears has only ever made it through 6k. That said, your picture shows unusual amounts of wear on the inner shoulder and you should get it checked.

Your lifetime kw usage would be helpful to understand driving style.

 

[lolachampcar]

I'm going to take a bit of a position here. It is my gut feeling that at least 15K miles should be possible if the tires are rotated from left to right in the rear so that all the tire is used. This assumes a driving style less than burn outs and traffic light launches on a regular basis. This number also accounts for the fact that the rears are doing a vast majority of all the braking (max regen).

I'm expecting 20K with 1.1 degrees of negative camber in the rear which I feel is perfectly acceptable. 4K is not acceptable provided you are not doing the above burn outs or launches. If you are getting 4K and you are not driving like its a rental car and you're 16 then I would think something is seriously wrong. Others are getting a lot more than 4K with the stock Tesla camber settings.

 

[carrerascott]

Spoke to service this morning. They said they need to speak to regional manager. End of day and no word from them. We are 3 hrs from service center, did pay for ranger service extended warranty etc.

Meanwhile the $102k car sits unusable in our garage and we have to resort to driving our ice cars.... Yuck.

 

[Dave EV]

Meanwhile the $102k car sits unusable in our garage and we have to resort to driving our ice cars.

You obviously need new tires - why aren't you having those installed and sort out the service issues later so you can continue using your car?

 

[carrerascott]

Response:

*I did receive a response from my regional manager. He advised that we would not be able to cover the replacement of the tires. However, we will be glad to perform an alignment check and make any necessary adjustments as needed if they are not within specs.

 

[carrerascott]

You obviously need new tires - why aren't you having those installed and sort out the service issues later so you can continue using your car?

Will have to order tires tonight. Not much of a local selection here.

 

[carrerascott]

Getting new tires (on my own) tomorrow. Tesla going to take the car next week to the service center to check settings. I really think tesla should cover at least some of the $600 for new rears if it's due to incorrect alignment or camber. A new $102k car shouldn't need service at 5500 miles...

 

[carrerascott]

Here were the current specs. Toe is way out of whack, they said it definitely caused the wear. This is a local shop, Tesla has not come down yet, they said they'll come get it next week but I haven't gotten any confirmation.

 

[Dave EV]

Ouch - so you have toe OUT on the rear wheels - a good amount of it, too. That would definitely cause wear on the inside of the tires, even without the stock camber settings.

Get that fixed and you'll get much better wear out of the next set of tires. The car should also feel more stable as well with the rear toe corrected.

 

[stevezzzz]

Maybe but shouldn't a performance family sedan from the factory get more than 5k from its tires?

I imagine if this happens to CR on their long term road test, they won't be so forgiving.

CR has 19" wheels and the stock Goodyear all-seasons. They probably will see some extra wear on the inside of the rears (as I do on my 19s), but with occasional rotation they should get more than 20,000 miles on a set of tires.

 

[lolachampcar]

This is the very first confirming evidence that something was wrong from the factory. There is no way a driver "knocks" toe out on both sides by hitting something or other driver error.

If possible, I'd shoot for zero toe in the rear (even though the spec is 2-5/32") and zero thrust angle (angle of the direction of the rears with respect to the direction the car travels). Range will go up and tires will last longer at the expense of a minor increase in "hunting" on grooved roads.

I have an email into Tesla Engineering asking about just how the rear upright moves when subjected to acceleration and deceleration loads along with bump steer (change in toe as the wheel moves up and down). The answer may affect setting the car to zero rear toe if something really awkward happens with the rear when loaded. That being said, I did set my rear at 0/0 when I did the camber links and had zero issue under hard loading.

THANK YOU FOR POSTING THE ALIGNMENT DATA