tonyc

Driving in today, the rear left tire shredded. I was in a tunnel and going around 80km/h and heard the sound of rubber hitting the car and saw strips of rubber flying behind me.

What do you think is the cause......?

They a Pirelli Pzeros and have had them about 5 years and are not badly worn.

Are they too old and brittle? It looks like the tire wall split.

Any advise appreciated.




TonyC

Streetfighter

Five years sounds like it is close to the end of its shelf life. You didn't see a nail, glass or anything sharp in the sidewall or treads? The tire looks kind of brittle to me from the pictures.

Colin 90 C2

check the date code and take it back to the dealer. that looks like a lawsuit waiting to be filed. (at least in the good old USA)

pete000

Thats normal for Pirrelli PZeros. They are not designed to last. Thats why they cost more than just about every other tire!

I like Conti's

boxsey911

Scary!

Looks like there has been some melt down - have you got all the heat shields in place on the exhaust?

Also, it's difficult to tell from the pics but if that's a left wheel, it looks like the tread pattern is running the wrong way which could be the result of a tyre not being mounted on the rim in the correct direction or the wheels have been put on the wrong sides (i.e. accidentally swapped).

kimo964

Was is possible that you were low on pressure and it just shredded it?

tonyc

I had just filled the tyres 10 minutes before hand.

I assume the tyres are facing the right way. The 'arrow chevrons' in the centre are pointing forwards.

I suppose this means I now need to get a full set of new boots.

ABQ Slim

60 minutes had an interesting piece about tire dates - here's an explanation:
http://www.mytwodollars.com/2008/05/...-code-on-side/

Can removing the heat shields really have an impact on the tires like that? I've removed my undertray , and all the foil covered foam surrounding my valve covers and plug wires, ostensibly for greater cooling effect. Do the tires take a heat beating when one does this?

boxsey911

That was just speculation on my part. I recently had cause to remove the shield on the manifold next the wheel and ran the car a few miles to my local Indy to have something inspected. As the manifold is very close to the wheel there, that got me thinking if it could lead to overheating over a prolonged period of the time? TonyC hasn't mentioned if this particular heat shield has been removed so I suspect not.

cobalt

I have had this happen to me before.

I had a large puncture in the sidewall causing total loss of air in seconds. Drove about 1/4 mile without air and the rim acted like a knife and sliced the tire exactly as you are seeing there. If you look at the lip of the rim it is scratched where it came into contact with the cording of the tire.

tonyc

Steve, not sure if the heat shield has been removed, not sure if I could tell either. Will ask my mechanic as he is sourcing my next set of tyres.

Anthony, I think you could be right about the slicing by the rim, but I did see a long string of rubber appear from behind me in the rearview. I thought my fanbelt had gone at first, only to find I still had power. The deflation was not fast and drove through the tunnel and parked off to the side once out about a 1/4 mile as well. The car stayed straight and was quite manageable.

cobalt

Surprisingly I thought the same thing. Although I never reached high enough speeds to become dangerous (35mph max) being a rear tire it suddenly felt sloppy in the back and when I pulled over I was surprised to see such a mess. Might have been a fast enough leak although Pirelli's have a relatively stiff sidewall and that is why it might have felt more secure than you thought initially.

Blu RS

Three questions: What is the actual size of the rear tire, what is the size/offset of the rear wheel, and have you had occasions when that tire was driven underinflated before? The point is that an 18" rim/tire combo can be extremely close to the cat on the left side with the consequence of excessive heat soak over time, particularly if the car is caught in traffic congestion. Similarly, a car driven with an underinflated tire causes stress and excessive heat in the sidewall which can ultimately lead to failure.

cobalt

Look to be 17" cup I's. Assuming the heat shield is in place and wasn't removed it should not have any impact on the tire. More importantly what is the tires size? The issue would be more of it rubbing with a too large tire than it drying out from the heat.

tonyc

Blu RS, the tires are 17", don't know the offsets but are standard cup wheels, nothing after-market. I've kept the tires inflated, they have never much much more than a couple of psi below 36. I inflate them at least once a month and drive the car about once a week. I do drive in congested traffic though. I just wonder whether they were just too old and brittle. Will look at the dates next time I drive it.