Topic: Recall on Agilis CrossClimate C-Metric by Michelin

[Slow_lane]

This just in. A rare mistake by Michelin. Leaving one to question if a 4 season tire really exists.

https://business.michelinman.com/why-michelin/safety-recalls/recall-april-2023

[ktm525]

The passenger tires and LT tires are fine. It was just the metric size tires that don't. I don't think this is a big deal here in North America. What vehicles are rolling on metric tires?

[HeliDriver]

The passenger tires and LT tires are fine. It was just the metric size tires that don't. I don't think this is a big deal here in North America. What vehicles are rolling on metric tires?

All of them? 

Okay, not all. Still might find a few old-school pickups running flotation sizes (eg. 31/10.50R15.)

[ktm525]

My bad. So these are light duty commercial tires that are not LTs and are not passenger  car tires. Sounds like a paperwork problem more than anything.

The bigger question is why does Michelin call them metric with an imperial wheel measurement? Stupid French. 



You say metric and Michelin and my mind goes immediately to the TRX. I rest my case.   

[HeliDriver]

It’s the standard, so it’s not just Michelin. All P-metric and LT-metric tires are metric. 

But I’d never heard of C-metric tires before. Looks like they’re for the Euro commercial vans like Ram Promaster and Ford Transit.

https://tirerack.com/upgrade-garage/what-are-eurometric-commercial-vehicle-tires

I read somewhere else that they did the snow testing at the wrong pressure. Sounds like when they redid the test at the proper pressure, the tires wouldn’t pass.

[ktm525]

It’s the standard, so it’s not just Michelin. All P-metric and LT-metric tires are metric. 

But I’d never heard of C-metric tires before. Looks like they’re for the Euro commercial vans like Ram Promaster and Ford Transit.

https://tirerack.com/upgrade-garage/what-are-eurometric-commercial-vehicle-tires

I read somewhere else that they did the snow testing at the wrong pressure. Sounds like when they redid the test at the proper pressure, the tires wouldn’t pass.

What's your rim size in metric and what does it say on the sidewall? Rather than a typical 245/65 R16 it should be 245/65R406.4 but I suspect...America. It really is weird how our tires are measured half metric and half imperial..


This C metric thing does explain those high load weeny tires you see on euro commercial vehicles. Vans perched up on those bicycle tires.

[me_2]

It really is weird how our tires are measured half metric and half imperial..

Yeah, it always bug me a bit this half & half system, i'm guessing it was a kind of give & take once upon the time..? 

[blur911]

It’s the standard, so it’s not just Michelin. All P-metric and LT-metric tires are metric. 

In the NA tire industry P-metric simply means passenger tire, as opposed to LT or heavier.

[HeliDriver]

It’s the standard, so it’s not just Michelin. All P-metric and LT-metric tires are metric. 

In the NA tire industry P-metric simply means passenger tire, as opposed to LT or heavier.

Are there any passenger tires that aren’t metric these days?

Also found this, which was interesting: https://www.consumerreports.org/cro/news/2011/08/what-is-the-difference-between-p-metric-and-metric-car-tires/index.htm

Didn’t know are straight Metric tires with no P or LT designation.

[ktm525]

Width in mm's

rim size in inches
load index in lbs
inflation pressure in psi

and we call them metric.   

Tire rack has a good explanation too. I always wondered how XL figured into the load rating. Rated higher with a higher tire pressure than SL

https://www.tirerack.com/upgrade-garage/what-is-maximum-load-for-a-tire



 

[me_2]

Load index (kG - Lbs) & speed ( kM/h - mph) rating are published in both units, Metric & imperial.
P-tire sidewall (usually?) shows pressure either in kPa & psi.
Ratio has no unit.

So, as you wrote
Width in mm's
rim size in inches

[HeliDriver]

Just because I’m doing the Yukon’s changeover right now… 

Max load on the Bridgestones is indicated on the sidewall in kilos, with pounds in brackets. Same for the pressure (KPa with psi in brackets.)

Load index is just a number, so no units there. It’s neither metric nor imperial.

Rim diameter is the only thing that isn’t metric. Michelin tried to change that with TRX, but as we know it didn’t exactly catch on. 

[me_2]

Ok, my bad, it was poorly worded...

Let me rephrase: Load index is a number (no unit) but has a specific load weight (kG - Lbs) associated to each one.

Same about speed rating, except it is a letter associated to a speed rated in kM/h - mph

[ktm525]

Ok things are in brackets lol. I wonder why the Americans put up with tire widths in mms? How did that become a thing for them?

Quick. What is your inflation pressure in KPa?   

Actually I take that back. The TPMS in my old Pontiac G8 had readouts in KPa likely because Australia.

[HeliDriver]

Haha, yeah I find the pressure readout in KPa kind of annoying in the Yukon. Can switch to Imperial to see psi, but then everything else is in miles and degrees Fahrenheit.  Would be nice to be able to pick and choose.

But, you get used to it. Just did the tire swap today, so can tell you off the top of my head that the rears are at 440 KPa and the fronts are at 320. Don’t ask me in a month though. 

Oops. It’s 420 and 340. 

[me_2]

On  tire pressure, i cheat myself  Last week right rear TPMS show low tire pressure, once parked to inflate the faulty one, i switched to imperial in Psi to validate everything back to normal before switching back to metric 

[blur911]

Haha, yeah I find the pressure readout in KPa kind of annoying in the Yukon. Can switch to Imperial to see psi, but then everything else is in miles and degrees Fahrenheit.  Would be nice to be able to pick and choose.

But, you get used to it. Just did the tire swap today, so can tell you off the top of my head that the rears are at 440 KPa and the fronts are at 320. Don’t ask me in a month though. 

Oops. It’s 420 and 340. 

Apparently some people think the readouts are in percentages, not PSI, so you fill your tires until it says 100