The tire didn't fall off, it was driven with severe low pressure, which builds up heat in the "squish" area (the thinnest part of the tire), and consequently un-vulcanized itself.

 

Still parts of the tire left.

 

Someone needs to pay attention when the car tells them the pressure is low in the front left tyre!

 

I had the same at 70+mph on the motorway. And I didn't ignore any warnings - from the chime saying low pressure to watching the tyre go flying off ahead of me into the distance was a couple of seconds! It certainly caught my attention. 😂

Lost a tyre!

Well, that was exciting... On the motorway yesterday doing 70.00mph (naturally) and there's a bang followed by the tyre pressure warning light coming on. I start slowing and move over. As I get into lane one, I see my tyre rolling down the road ahead of me. Polestar Assistance were excellent -...

www.polestar-forum.com

 

Wow, seems like the indirect tpms sensors aren't working very well.

Bmw has used indirect for years and it's worked well, but maybe geeley hasn't figured out as well.

 

Wow, seems like the indirect tpms sensors aren't working very well.

Bmw has used indirect for years and it's worked well, but maybe geeley hasn't figured out as

The only BMW to use an indirect tpms is the X5 for a few years in the early 2000's. Every other model, and the X5 after that, has used sensors in the wheel. Are you perhaps thinking Audi? Audi is an avid user of indirect tpms.

Personally, I'll take a sensor in the wheel, especially if the system is smart enough to give individual pressures per tire.

 

I've driven on low pressure tires many times over the course of decades of driving, for more than a mile, and can't say I've ever needed a pressure monitoring system to tell me there was a problem. It was very obvious. But that was with a slow (eg, nail in the tread) leak, and there was still some pressure left in the tire.

If things happened in a matter of seconds, I would say this was a catastrophic blow out at high speeds.

 

Yep, my issue was instantaneous and the complete tread cleanly left the rest of the tyre. The two sidewalls were still on the rim.

 

I was getting ready to respond to your first post, then you covered what I was going to say. Depending on the speed you're driving, and how fast the air loss is, the failure can come on almost instantly. It sucks. I've had it happen to me as well.

 

Thinking about this. Abs based indirect systems rely on measuring and calculating deviation in rotation from a set standard. Once the deviation exceeds a certain level it triggers the. Alert.
The shorter the side wall (think 40s., 35s) the smaller the variances between a properly inflated tire and a low inflated tire are gonna be so the more accurate the calibration might need to be.
My Audis had the indirect one and on the s 5 with 35s it often gave me false alarms (in addition to a bunch of real ones - thank you nyc potholes) and on the A7 with the 40s I never had an alarm that wasn't warranted
I like the fact that it makes tire replacements easier for shops

 

Time to check my tire pressure with a real gauge.

 

Nope - was only six months old.

Lease company paid for the replacement. If it had been my own personal out of pocket expense, I might have argued harder!

 

I had a TPMS warning, whilst driving in town at 30mph, drove about 250m to the petrol pump and the tyre was virtually flat with air hissing out which stopped within a minute of me pulling up.

If I had been doing 70 don’t think there would have been anything lefT of the tyre or the alloy. 3hr wait for Volvo recovery, 45 min drive to Volvo on the back of the truck and 3hrs waiting at Volvo for the tyre change. Probably would have been changed faster but I Insisted on inspecting the alloy and the new tyre before they put it on. old habit from previous experience of getting puncture within a day of a tyre change.

 

The fact that these tire treads have completely separated from the sidewalls in a similar manner on multiple vehicles more concerning. Slightly under-inflating or slightly over-inflating shouldn't cause this problem, and you have to build up a hell of a lot of heat to break the steel and poly belts that fully wrap from the sidewalls and around the tread.

Absolutely! I would raise holy hell with the tire manufacturer. This just shouldn't happen unless the tire was seriously underinflated.

 

With EVs weighing more than normal passenger vehicles, tire manufacturers probably need to beef up their construction a bit, especially for sporty EVs like Polestar's.

 

There are no steel belts in the area where the tire came apart, FYI.

Yeah. But it sure looks like these are flat out failures of the tire manufacturing process, as opposed to some user error.

 

I'm not arguing with you, I'm just making sure you know if you're going to "raise holy hell" with the tire manufacturer, it's plural. Two manufacturers.

 

I keep on seeing statements in the media and this forum about EV's being heavy.
I concede that they are heavy but they are no heavier than many widely sold ICE vehicles.
The Audi A7/8, Q5/7, RS6/7
Toyota Sienna,
Infiniti QX60/80
VW Taureg
Volvo S90, XC90
and many more
weigh as much or more than a P2.

So the weight is not the key factor in EV tire failures but, as others have mentioned, the availability of substantially higher torque is likely the key player here.

Let's stop with this "our cars are heavy" talk and focus on the hp/torque.

 

I keep on seeing statements in the media and this forum about EV's being heavy.
I concede that they are heavy but they are no heavier than many widely sold ICE vehicles.
The Audi A7/8, Q5/7, RS6/7
Toyota Sienna,
Infiniti QX60/80
VW Taureg
Volvo S90, XC90
and many more
weigh as much or more than a P2.

So the weight is not the key factor in EV tire failures but, as others have mentioned, the availability of substantially higher torque is likely the key player here.

Let's stop with this "our cars are heavy" talk and focus on the hp/torque.

Hp/torque didn't cause the issue the OP showed. Driving on a low pressure tire, which causes an increase of heat to the point of failure, did.

Respectfully, and by the definition of the word only, there's a lot of ignorant information in this thread.

 

With EVs weighing more than normal passenger vehicles, tire manufacturers probably need to beef up their construction a bit, especially for sporty EVs like Polestar's.

Every tire has a load rating index on the sidewall. Are you questioning whether the OEM tire choices load ratings are sufficient for the weight of the vehicle?

 

There are two indicators of tire construction. One is the load rating, the other is load index.

Load range (e.g., XL for Polestar 2 OE tires) corresponds to the number of plies in the tire and the resulting pressure they can hold.

Load index (e.g., 99V for 2023 PS2) is a number and a speed rating, and refers to the amount of weight each tire can carry when inflated to its maximum rated pressure. 99 corresponds to 1,709lbs per corner. You have to take cornering and impact forces into account here - you drive it hard or you drive on shitty roads, you need a higher number to provide sufficient margin in tire strength to support the vehicle. Doesn't mean the tire will blow when you take a corner, but running a lower load index on a heavier vehicle will absolutely mean faster wear and magnification of any manufacturing defects.

The Michelin Primacy all season tires on my 2024 have a load index of 102V, corresponding to 1,874 lbs per tire. Additionally, they're designed to operate at a wider operating temperature range, and so won't crack and separate at low temperatures.

 

It's a combination of both. My 2017 Land Rover Discovery has a curb weight of 4850 lbs or thereabouts - it's not the 3-row and doesn't have a locking rear diff. The upper end of this vehicle's curb weight is 4,916lbs.

The Polestar 2 has a curb weight of 4,650 lbs.

The footprint and the physical size of the PS2 is far smaller than the Land Rover Discovery. A Tesla Model S P100D is heavier than my Land Rover. A Hummer EV has a curb weight only a few hundred pounds less than what would require a special driver's license in the US to operate.

An Audi A4, which is about the same size as the PS2, has a curb weight of around 3,650 lbs. So around 250lbs less at each corner. Adding 250lbs of sprung mass on every tire, subjected to not only more momentum but also more hp and torque, is a recipe for very fast wear and magnification of any manufacturing defects in the tire.

The Lithium Ion batteries are heavy. The structures necessary to protect the Li-Ion batteries from damage are heavy. That is why EVs, per cubic dimension of your choice, are heavier than equivalent ICE vehicles. It's an inconvenient truth, to be sure, but a truth nonetheless.

Add in the caution against driving on the performance tires at temperatures below 20F (who got that tidbit at handover?), and you're looking at premature tire failure.

 

Can you find anywhere on the screen the actual pressure of the tyres? It only says "all is well".
I checked the tire pressures before my holidays and they were quite below the pressures on the door sticker.
BMW for example shows the pressure for each tyre.

 

Unfortunately, no. The Polestar 2 uses an indirect TPMS that does not have a physical sensor in the wheel, yet uses the ABS system to measure rolling circumference of the tire, which changes with pressure increase or decrease. It's very important to "relearn" the TPMS if pressure is ever changed in the tire.

 

Making special EV tires is different than building tires to withstand cornering and torque forces of a heavy EV with gobs of torque. While the Polestar OE tires are all XL and V rated, that doesn't mean they're necessarily fit for purpose. Paying tire manufacturers to design special tires (as Porsche has done for the Taycan) vs fork an existing design for noise reduction can mean a measurable difference in vehicle price.

Are you suggesting they made a tire for an EV and ignored important aspects of the car?

This warning from the Polestar-specific Contis is instructive as to why some NA markets are now getting all season tires as standard on the 2024 models:

Which they should have done all along given the nature of this market.

mute

moot 😉

 

Are you suggesting they made a tire for an EV and ignored important aspects of the car?

Automakers have to make all sorts of trades in design. They need to cut cost and keep margin high, while meeting regulatory requirements for the markets they sell in.

The only regulations in the US at the Federal level that have to do with tire strength testing, are so that a 99 load index tire is at least as strong as that load index. It's up to automakers to choose tires for their vehicles.

 

Everything is a tradeoff with cost in mind. I guess the car could be safer if they didn't cut some costs

And so you are suggesting this is a Polestar problem for choosing a tire inconsistent with the design needs of the car.

 

This is what I have on my 2022 P2: Michelin Primacy All Season 245/45-19.

 

Share a link to this exact tire, or post a picture? I'm not saying you don't have it, I'm just curious because I can't find the exact tire online.

 

I have the 20s but this is my tire.

 

 

That's for the link and pictures. Very interesting that neither Tire Rack or Michelin NA website lists the 19" tire. Seems like this would be very difficult to source, at least for now, in the event you had to replace a tire.

 

https://www.anrdoezrs.net/click-100...chelin&tireModel=Primacy+A%2FS&sidewall=Blackwall&partnum=445HR9PASXL&tab=Sizes

 

That's not it. The linked tire is a 102H rated tire.

 

When I replace them, I'll get four of these:

MICHELIN PILOT SPORT A/S 4 - Vehicle Tires | Michelin USA

Learn about the MICHELIN car tires, its benefits, customer reviews, current offers, and available sizes in the USA. Explore all the features and advantages of the PILOT SPORT A/S 4 tire.

www.michelinman.com

 

Same. I already have the Michelin tires on the wall in my garage. I'll store the Continental tires to install at the end of my lease.