[Two] New rear tires and now autopilot weaves

[adayley]

I had to replace the rear stock tires with a pair of Michelin Pilot Sport All Season 4 tires. Today I used Autopilot on a 60 mile round trip. The car was weaving slightly but noticeably in the freeway lanes. Just enough to be annoying. It didn’t do this before. It held a nice steady line in the lane.

Is a wheel alignment is needed? What else should I check or investigate?

 

[Kimmi]

My guess is that the tires are reacting to the rain grooves in the pavement?

 

[adayley]

My guess is that the tires are reacting to the rain grooves in the pavement?

Decent guess, but not in my case. The freeways had varied surfaces including rubberized asphalt, asphalt and concrete with the grooves. The weaving happened on all of them.

 

[KenC]

Make sure tire pressures are equal and make sure lugs are all tightened equally, other than that, alignment.

 

[lbowroom]

What happens if you rotate back to front?

 

[adayley]

What happens if you rotate back to front?

I don’t expect to do that. The front tires are original with the car. They were rotated to the front a few weeks before nails found the rear tires.

 

[thesmokingman]

Isn't this a problem to take up with the tire installer?

 

[adayley]

Isn't this a problem to take up with the tire installer?

Yes. And the installer doesn't do alignments (Discount Tire) so I will have to go to someone else, anyway. I will ask them to cover the cost.

 

[Darmie]

You keep mentioning alignment however your issue only appeared when you changed rear tires.

What happens if you rotate back to front?

I know you want to keep the tires where they are but this is a good idea to help trouble shoot or narrow down if the new rear tires are what is causing the issue on the back.

Have the new tires looked at carefully. Even new tires can have a bad belt and cause the slightest bit of weaving.

 

[adayley]

You keep mentioning alignment however your issue only appeared when you changed rear tires.


I know you want to keep the tires where they are but this is a good idea to help trouble shoot or narrow down if the new rear tires are what is causing the issue on the back.

Have the new tires looked at carefully. Even new tires can have a bad belt and cause the slightest bit of weaving.

Good ideas I didn’t think about. I’ll look into this, too.

 

[jjrandorin]

Yes. And the installer doesn't do alignments (Discount Tire) so I will have to go to someone else, anyway. I will ask them to cover the cost.

Discount tire (your installer) is supposed to cover the cost of your alignment, because why exactly? Just wondering where that comes into play, if in fact it is alignment.

 

[adayley]

Discount tire (your installer) is supposed to cover the cost of your alignment, because why exactly? Just wondering where that comes into play, if in fact it is alignment.

In my experience, changing two tires has not ever triggered a need for alignment. My naive assumption, then, is that they tire installer accidentally caused the need for an alignment, that they did something they should not have done. Again, my expectations may be out of line.

My current plan is to take the car to a shop that can check and do the alignment. I will also ask them to inspect the new tires, in case the tires have some kind of defect.

 

[jjrandorin]

In my experience, changing two tires has not ever triggered a need for alignment. My naive assumption, then, is that they tire installer accidentally caused the need for an alignment, that they did something they should not have done. Again, my expectations may be out of line.

My current plan is to take the car to a shop that can check and do the alignment. I will also ask them to inspect the new tires, in case the tires have some kind of defect.

Shrug...

Most places that offer tire changes and alignments will "recommend" an alignment. This is partially because they want the money, but....

Do I Need an Alignment with New Tires? | Firestone Complete Auto Care

Wheel alignment helps tires perform better & last longer. But how about new tires? Do they still need an alignment? Find out, with Firestone Complete Auto Care.

www.firestonecompleteautocare.com

Here is another question. Do you have 2 different types of tires on your car? Do you have the stock tires in front and these other tires in the back? It reads like you do. If so, My thought would be that is your issue.

 

[Darmie]

Ensure they are set up for a 4 wheel alignment. I know any alignment shop knows how to align a tesla but I would ensure they know the specifications.
Have a look here for M3 specs.

Alignment specs attached

Had the alignment checked today at the SC, thought people might be interested to see the specs which are in the attached pdf. Front L/R: Camber: -1.0 - -0.1 Caster: 4.7 - 6.7 Toe: -0.2 - 0.1 Front Total: Cross camber: -0.3 - 0.3 Cross Caster: -1.0 - 1.0 Total Toe...

teslamotorsclub.com

 

[adayley]

Shrug...

Most places that offer tire changes and alignments will "recommend" an alignment. This is partially because they want the money, but....

Do I Need an Alignment with New Tires? | Firestone Complete Auto Care

Wheel alignment helps tires perform better & last longer. But how about new tires? Do they still need an alignment? Find out, with Firestone Complete Auto Care.

www.firestonecompleteautocare.com

Here is another question. Do you have 2 different types of tires on your car? Do you have the stock tires in front and these other tires in the back? It reads like you do. If so, My thought would be that is your issue.

Thank you for the alignment reference.

As you gathered, I DO have 2 different tires on my car. The front has two of the original Michelin Primacy MXM4 tires. These tires are hard to find so, when I got two nails in one rear tire, I replaced both rear tires with something else. I put two Michelin Pilot Sport All Season 4 tires on the back.

If my car cannot handle two different tire pairs, that is disappointing and expensive. I did replace one perfectly fine tire to keep the rear axle consistent. Replacing all four tires because one tire got an unrepairable hole is not reasonable, to me. Though, you could be right.

 

[jjrandorin]

Thank you for the alignment reference.

As you gathered, I DO have 2 different tires on my car. The front has two of the original Michelin Primacy MXM4 tires. These tires are hard to find so, when I got two nails in one rear tire, I replaced both rear tires with something else. I put two Michelin Pilot Sport All Season 4 tires on the back.

If my car cannot handle two different tire pairs, that is disappointing and expensive. I did replace one perfectly fine tire to keep the rear axle consistent. Replacing all four tires because one tire got an unrepairable hole is not reasonable, to me. Though, you could be right.

"handling" 2 different types of tires, and "riding exactly the same" with two different pairs of tires are not the same thing at all. The car drives, but it doesnt handle exactly the same, which is not surprising at all, and impacts pretty much every car in this situation known to man, to some degree or other.

You are just noticing it more when you use autopilot.

 

[adayley]

"handling" 2 different types of tires, and "riding exactly the same" with two different pairs of tires are not the same thing at all. The car drives, but it doesnt handle exactly the same, which is not surprising at all, and impacts pretty much every car in this situation known to man, to some degree or other.

You are just noticing it more when you use autopilot.

I don’t expect handling and ride to be exactly the same as before. I do expect the car to drive straight when each axel has the same model tires with similar amounts of wear.

 

[jrweiss98020]

Rotating front-rear will give you a data point: The wandering will either get better, get worse, or stay the same. If it changes at all, it is likely because of the difference in tires. There are many reports of weird handling when 1 pair of tires is replaced. I suspect it is because of a difference in tire diameters, and the RPM sensors that control torque vectoring and other anti-skid functions are VERY sensitive to it.

 

[adayley]

Rotating front-rear will give you a data point: The wandering will either get better, get worse, or stay the same. If it changes at all, it is likely because of the difference in tires. There are many reports of weird handling when 1 pair of tires is replaced. I suspect it is because of a difference in tire diameters, and the RPM sensors that control torque vectoring and other anti-skid functions are VERY sensitive to it.

Thanks for that observation.

Makes me think that maybe recalibrating Autopilot would help.

 

[Occhis]

How does the car drive when autopilot is not engaged?