Tire change at 20k

[Beachybumm]

I just bought a used M3 with 20k miles. I had it inspected and was told the rear wheel tread was down to the tire tread bar, which meant I had about 10-15k miles left before needing a change.

I brought it to a tire store today to have the car aligned because it was veering to the right. They did the alignment, then told me I needed to change the tires immediately because they were down to the tread bar.

I called back the inspection place, who'd told me the tires didn't need immediate replacement, and they said they'd never tell me what to do or not do re tires. But also said I probably still have about 20% use left.

They also said I shouldn't have had the car aligned if I was going to get new tires, because the front tires would be rotated to the back and the new tires would be put in their place (in the front). This, they said, would throw off the alignment and I'd need to redo it. But at the tire place, they said I wouldn't have to re-align with new tires.

My questions are as follows:

1) Based on the description above, do I need to change the back tires immediately?
2) If I change the back tires, is there a reason they wouldn't be replaced by the new tires? I don't understand why the current front tires would move to the back.
3) Do I really need to do a whole new alignment if I replace the back tires?
4) The tire store said that even though they did the alignment, Tesla has some kind of proprietary way of recalibrating that would need to be done. Is this true?
5) Inspection company said if I leave the front and back tires as-is, I should only rotate the front tires side-to-side. Tire store said they don't do that. And that it wouldn't make sense to do that.

Any help would be greatly appreciated.

 

[MasterC17]

If the rear tires are worn to the tread bars then yes, they need replacement immediately.

New tires generally go in the back, not the front.

At 20k miles I would do an alignment with new tires.

Yes, Tesla resets the steering angle sensor, but it isn't necessary either.

Inspection company sounds like they have no idea what they are doing to be honest.

 

[XLR82XS]

Did you look at the tires before you bought the car? If the fronts are remotely close to replacement I'd get an entire set. Not worth compromising with tires.

 

[Gasaraki]

You really should be replacing all 4 of your tires. Maybe you don't have to if it's the SR model. But still, replace all four and rotate the tires.

 

[Sam1]

the wearbar is there to let you know when it's time to change the tires. When you go down below that, you're somewhat effectively trying to turn your tires into slicks

 

[KenC]

My questions are as follows:

1) Based on the description above, do I need to change the back tires immediately?
2) If I change the back tires, is there a reason they wouldn't be replaced by the new tires? I don't understand why the current front tires would move to the back.
3) Do I really need to do a whole new alignment if I replace the back tires?
4) The tire store said that even though they did the alignment, Tesla has some kind of proprietary way of recalibrating that would need to be done. Is this true?
5) Inspection company said if I leave the front and back tires as-is, I should only rotate the front tires side-to-side. Tire store said they don't do that. And that it wouldn't make sense to do that.

Any help would be greatly appreciated.

1) Yes, when your tires hit the wear bar, you replace them, because if you hit standing water, you will hydroplane.
2) You always put your newest tires on the rear, because they provide the most grip; and your average driver can handle understeer better than oversteer.
3) No
4) Not sure
5) Generally, Tesla rotates front-to-back. If you look at Michelin's website, the OEM tire mfr, recs a cross-pattern. Have never heard a side-to-side rec'd.

 

[lbowroom]

This just gets more entertaining as we go.

do you have an SR, SR+, Dual Motor, Or Performance? Factory wheel? 18, 19, or 20”?

 

[ULEWZ]

Tires loose grip as they approach the wear bars, so I always replace when close and never go past the wear bars. I highly doubt you have 10,000 let alone 15,000 miles left. And replace them all, not just two.

 

[lbowroom]

Only in the wet, unless you think slicks have less traction

 

[ULEWZ]

Only in the wet, unless you think slicks have less traction

That is not true in my experience. I run with a corvette group and we all can feel when the tires loose traction, usually about 5,000 miles before the wear bars. The rubber changes and just does not grip, even in the dry. I estimate about 10% less grip which will be fine for those that don't hit the twisties.

 

[Arctic_White]

That is not true in my experience. I run with a corvette group and we all can feel when the tires loose traction, usually about 5,000 miles before the wear bars. The rubber changes and just does not grip, even in the dry. I estimate about 10% less grip which will be fine for those that don't hit the twisties.

Well said. I generally replace all four tires when they have ~40% treadwear remaining. I then sell these tires to help offset the cost of new ones.

Remember folks: tires are the ONLY thing that connects our beloved cars to the road. Do not skimp out on getting high-quality tires. Preventing even one accident over the course of your driving will make the investment in new high-end tires worth it.

 

[Vaillant]

Why must you replace all four? There’s no center diff in a Tesla, so i don’t see a reason why you would need to do that.

As far as when you replace, it depends on your weather. Where I live I won’t be driving in rain until November, so there’s no risk of hydroplaning. Other places get buckets of rain in the summer, so then it is a safety issue.

 

[lbowroom]

Unless the rubber compound changes at the wear bars, there is no basis for dry traction to change.

 

[ULEWZ]

It could be a bunch of reasons. Maybe the tire heat cycles over time, changing the characteristic of the tires, Maybe as the tire wears, it looses thickness, which places the contact patch closer to the steel belts, which flex differently than a new tire. Could be loads or reasons, I think we should get myth busters on it. I also find the ride gets harsher as it gets closer to the wear bars, and the tires tend to get flats easier (can't prove that one, it just seems to happen more when my tires wear down). Point being, for guys that don't push the limits of their cars they will probably never notice the difference. For people that like to hit the twisties like myself and my friends, it is painfully obvious when the tires go off. They squeal more in turns, and you can actually feel the car slipping when it would normally be railing. So just to reiterate, most people that drive their cars normally (IE without gusto) will not notice the difference unless it is raining. That's my story and I am sticking to it. And the reason to replace all four tires is so the car behaves equally at all 4 corners.

 

[SelmaTeacher]

I do notice that our Model 3s have VERY soft tires. If you are getting uneven wear on your tires then I would check the tire alignment , regardless of the mileage.