2 yrs old for 'Z' rubber?
 

I have a set of Mich PS ribs on the front of the 02 C4 cab that have plenty of tread but I was in the process of replacing the rears (for a dif reason) and it was suggested to me that the age on the fronts (almost 2 yrs old) would be a reason to do those also (rubber hardens, less adhesion, more noise, etc).........does this sound plausible?.....I guess I may have heard it before but wondered if these trates were noticable at 2 yrs............TIA.

Re: 2 yrs old for 'Z' rubber?
 

Greg, two years is nothing. Go ahead and keep them if that's what you'd rather do.

Thanks......I think I will (for now).
I'm already going to have a hard enough time explaining to my wife the $3,000 I need in other tires :D

Its better to ask for forgiveness than it is to ask for permission.

Porsche owners should live by that.

:bigbye:

I was under the impression Porsche recommends a maximum of three years for rubber no matter how many miles used.

I think one more concern is with the C4. Doesn't Porsche recommend tread deapth to be within a certain tolrerance between front and rear tires. Most C4 owners I believe end up changing out all four tires at a time although front tread is still good.

Regards,

http://forums.rennlist.com/upload/tire_life.jpg

http://forums.rennlist.com/upload/tread_depth.jpg

I would be more concerned if they were not regularly used. Tires like many other components in a car are meant to be used and if they are not are more prone to failure. Personally, I have never had a set of any rating of tire last two years on my car, so for me it has never been a concern.

I agree with Viken; two years is nothing. Some brand new tires come that old. Of course, they've never been driven on, and such tires have a long shelf life.

I just replaced 6 year-old original S-02s, and the rears were not even to the wear bars yet (the fronts had plenty of tread, of course). They were the longest wearing tires I've ever had on a 911, and I use about 1.4 degrees of negative camber. Yes, they were getting hard and slippery. I can't really say how many miles were on them because I drive to and from driving events on my other tires. However, the odo turned 30k miles during that time, so maybe 18 or 20k miles were on those tires. Bet my new tires don't last that long.

I was up at Hairy Dog Grrrage in CT a couple of weeks back and Daniel Jacobs mentioned that Porsche had recently reduced acceptable use from 6 years down to three years from manufacture date. He also made a comment that Porsche had released info regarding tolerances between front and rear tire tread depths for C4's. He mentioned something about C4 owners having an issue with the 4 wheel drive system if tread depths varied by more then a certain % from front to rear.

Was he incorrect in making these comments? I think 3 years is a rediculously short period of time considering cost but he claims the new tire compounds are showing evidence of drying out faster.

He is not the only tuner shop I have heard this from.

Just curious if you heard anything or Just stick to what the manual says?

Most likely. I am not aware of any recent TSB's indicating changes or even the AWD issues. In fact, the AWD tread depth differences are a non issue as there is an acceptable tolerance built into the system. At the very worst, the difference in diameter between front and rear tires is going to be 4-5 mm. Furthermore, Porsche is still printing the above in their owner's manuals. That came from a 2004 MY manual.

I thought three years sounded rediculous. At that rate I would be luky to get 5-6k out of a full set of tires.

Appreciate the info.