The CPO'd 13 C4S i just picked up has about 10,500 miles and the front tires (stock pirellis) are displaying what appears to be cracking or dry rot. The tread depth is 5.5-6mm and passes the cpo checklist.

I'm guessing they are the original tires and the cracking / dry rot is in an age thing, but would greatly appreciate input as I wouldn't expect dry rot on 4 year old tires. I'm daily driving the car (and absolutely loving it!) but am thinking I should swap these out asap, unless someone tells me it's normal and fine for these tires. The car has a brand new set of rears on it.

Thanks in advance for your input!

ummjmN0.jpg

 

Using summer performance tires at temperatures less than freezing may cause cracking. This may be the cause of the cracking present here. See the Tire Rack information on the subject.

http://www.tirerack.com/tires/tirete...jsp?techid=273

 

Not good. I'd replace. The grip on these will be compromised. Plus, these tires only have a 4-5 life regardless of miles on them.

 

What is the 4 digit date code on the tire?

Maybe they are under warranty?

 

What's the date code on them? Are they really 4 years old or are you judging that by the car's age?

Would bring it back if you really just bought it. That isn't right.

 

I need to check on the date code, age was an estimate based on it being a 13. I'll go find the date code.

The car has lived it's life in greater LA area so doubtful they've been driven much in sub 45 degree temps. It's like year around summer here ;P

 

The pictured tire has a date code of 3412. The other front's date code is 4412.

Assuming the typical manufacturing marking is workweek / year:

workweek 34 corresponds to ~August 19th 2012, or roughly 4 years 1 month

workweek 44 corresponds to ~October 29th 2012, or just under 4 years (by 1 week).

 

If your car was just CPO by a Porsche dealership take it back and talk to your salesperson ask them to replace the bad tires. If the Porsche dealer won't replace them call 1-800-Porsche they will give you a action number and talk with your dealership about the CPO inspection. If you pick up your car from a other type of seller you will need pay to replace the tires..

 

I've never heard a clear answer on how a CPO classifies tires other than tread depth or N0 rating. Would be interesting to find out.

 

I've communicated the issue to my salesperson via email tonight. Will update on response.

C4SJohn, - yes was recently CPO'd by a porsche dealership.

 

As part of the CPO process the check list has a inspection for tires 1, do they pass or fail. 2, are they Porsche approved tires. 3, measure tread. The Dealer should have given you a copy of the inspection CPO check list. It is to be sign by both their service manager and the tec that reviewed/inspected your car. The picture of the tires you posted above ( tires are unsafe should have fail ) I am sure the dealer will fix this oversite for you. Let us know....

 

A seeing eye dog would have picked up on those cracks.

Someone needs to get their eyes checked.

Don't settle for anything less then new tires all around.

 

With no belt material showing, I'll bet the dealer will tell you that the cracking in that photo is considered superficial and not a defect. It is more likely caused by excessive sun exposure than cold, especially if you live in LA.

Probably better to replace performance tires every 5 years whether they appear to need it or not. But again, good luck getting a dealer to agree to that when his bottom line depends on him not agreeing with it.

 

PZeros do not age well and those cracks on the outer blocks are common on tires more than 3 years old - it's like Pirelli designed them with a two year life-cycle in mind. I had exactly the same thing on my R8, see below. Heat cycling, not necessarily in warm or cold climates, causes premature embrittlement. Although they may be legal (I can't confirm that) as its only the tread block and not the sidewalls that are cracked, as STG says, you will certainly not be getting the best out of a high performance car with that rubber. When ambient temperatures are low and the tires have not warmed up, you will have poor front end grip and the ride quality will also be affected. I can say with high certainty that you will feel a big improvement in ride quality when they are changed out.

 

I have a similar issue on goodyears that came with the car (24th week of 2012). Mine look new and no cracks, but they have as much grip as a wood wheel ;-) You and I should replace them, in fact I have my car booked for Michelin Super sport this w/e !