How does this happen? Tire content

Just started using smugmug, so hopefully the pictures work.

Just some info:

Dunlop Direzza ZII
Manufactured: Late May 2013
Purchased: 9/18/13 from Tire Rack
Installed: Within a week of purchase

Inflated to 32 psig
Never run low on pressure
Driven less than 5000 miles
Car is garaged

Here is what happened today while doing 80mph on the Turnpike:

The before:

I was about 5 miles from home and all I could do was pull over on the fast side emergency lane, so I decided to put the spare back there. I know the clutches on the LSD where probably hating me the whole way.

I am ordering four new tires tomorrow as I don't really trust these anymore. I will also see if the Tire Rack would help me get these back to Dunlop to do some failure analysis. I am not looking for anything in exchange other than to know why did this happened.

I see the pictures don't work. I am trying to fix it, give me a minute.

In reply to Slippery:

I'm no expert, but my guess is age. I'm starting to realize tires just don't really last that long, and at least with newer tires, they don't always show any sign of impending failure.

Could be a defect in the tire, since the sidewalls and tread section completely parted ways.

Might be worth checking the carcass for any punctures. My guess is it was run with low pressure, unbeknownst to you.

I have never had a tire fail like that. I am not convinced it was age, but its possible.

BTW, the spare that got me home was made in West Germany ...

conesare2seconds wrote: Might be worth checking the carcass for any punctures. My guess is it was run with low pressure, unbeknownst to you.

I check the pressure on them pretty often. One thought is that it could have gone flat a few miles before this happened? I kind of think I would have noticed given that it was back there on a RWD car.

I had a tire go down at speed when the valve stem failed suddenly (apparently there was batch of bad Chinese ones that caused quite a few problems). Take a look at the valve stem and see if there's any signs of degradation.

Well, that's scary, and I'd say you are pretty lucky.

I wonder if Dunlop would be open to checking them out. I will bounce it off of the TR people tomorrow.

with that offset, any possibility that your rear suspension is too soft and the tires were contacting part of the wheel arch? I've had tires do that before without rolled fenders and run a groove down the tire right about where yours split. I assume you'd notice such contact, but figured I'd throw it out there.

Did you hear a pop?

with an LSD, you may never feel a tyre going low until it is too late. I had that happen with my old 318ti. Had no idea it was low until I took a corner and the rear tried to slide out from beneath the car. It was also when I discovered that my car had no spare (318ti's spare is carried UNDER the car and I had just bought it)

Well that is wild and scary. No way it's "just age" on a 4 year old name brand tire. Both sides separated so no way it was wheel arch contact.

Pete Gossett wrote: In reply to Slippery: I'm no expert, but my guess is age. I'm starting to realize tires just don't really last that long, and at least with newer tires, they don't always show any sign of impending failure.

4 years isn't nearly old enough for that kind of catastrophic failure IMO.

irish44j wrote: with that offset, any possibility that your rear suspension is too soft and the tires were contacting part of the wheel arch? I've had tires do that before without rolled fenders and run a groove down the tire right about where yours split. I assume you'd notice such contact, but figured I'd throw it out there.

Does not rub at all. I have Billy Sports and H&R Race springs.

I went back and checked the tire closely, this is what I found:

inside:

This supports conesare2seconds and mad_machine's statement.

Nick (Bo) Comstock wrote: Did you hear a pop?

Yes, the tire popped. I coasted about 1/4 mile as I could only apply light brakes or the rear end would get all loose.

Low pressure, no doubt at all.

That's the way a flat tire goes if left, looks like that was quicker and more complete that normal but.... yes.

Yeah, the sidewalls separated so neatly because they're so stiff.

A softer construction tire would have looked all shreddy.

I recently saw a guy driving down the highway on a flat tire. He ignored my attempts to alert him to the problem, and countinued to drive at speed. I watched his tire do exactly that a couple miles later.

That is exactly what my rally tires would look like after taking a rock between the caliper and wheel relieving all air pressure. If you were luck and on asphalt, you would get a smell about 30 seconds before full separation. For some reason it always seems to happen to newest, nicest tires

I saw this thread last night and didn't have time to comment. I thought you'd find a puncture. I suspect that whatever made that hole was actually in there for a a bit and that when it came out at speed the tire lost pressure rapidly and then separated at the sidewall. The inside doesn't look like it was run at low pressure.

I don't think that there was defect of any sort and I wouldn't hesitate to run the others.

Just for reference I once had a flat in the back of my Samurai, which has a very aggressive locker in the rear, and I thought I just had a slight alignment problem. Someone noticed that one of my tires looked saggy when parked on an incline, I checked it, 0psi. The sidewall was plenty stiff enough to keep the wheel off the ground but it wasn't obvious that I had 12~14psi on one side and 0 on the other.

Glad you, the car and your RS's are okay!

Adam