jfort

My clutch was slipping. I replaced it, flywheel, pressure plate, etc. over the winter. I have only 35K miles and I am not hard on the clutch. As expected from my readings, it wasn't the clutch, it was the pressure plate. 3 or 4 of the "tynes" were oddly bent. Works fine now.

sandwedge

Tough to go on mileage on this. Some people think they're really good at driving a manual when instead they suck at it. Or you can be really good at it like Bruce for example who got close to 200K miles on one clutch. Impressive. Other variables are how the previous driver treated the clutch if you buy a preowned car and where it was driven. Mostly city or mostly highway? I'd imagine someone living in San Fransisco parking streetside on a hill every day, sometimes multiple times would put a lot of wear on the clutch no matter how good a driver he/she is. So not an exact science but based on recollection of clutch threads here over the years it seems like somewhere in the 40,000 to 60,000 mile zone is a common time of replacement. Some get more and others get less. The lowest I recall reading about on RL was around 20,000 miles and it was due to abuse as opposed to mechanical failure.

oronymo

Finally bit the bullet and had a new clutch put in at 82k miles. The clutch was heavy and crunchy/chattery when I bought it a year ago so I knew it was in my future at some point.

The disc was pretty much worn and the pressure plate and throw out bearing were worn out (probably the main culprits to the poor driving feel). Flywheel is fine as is the RMS.

Man does the car drive SO MUCH BETTER. Buttery smooth pedal travel and clutch engagement. Much lighter and easier. Wow. Feels like brand new off the lot. Was definitely worth getting it done.

ADias

A heavy clutch may also be a failing master cylinder...

oronymo

In my case, slave and master cylinders all checked out.

FZP

A clutch can fail at anytime without notice. My failed on Thursday just gone with no slipping whatsoever. I'm waiting to hear back, but Porsche believe that the friction plate material has delaminated or the metal fingers have snapped. Either way I'm certain I'm going to need a flywheel as well.
According to my local Porsche dealer 40k miles is an average lifespan, mine happened at 47k.
My clutch failed going from 2nd to 3rd coming out of a round about. I've never done a launch from dead stop and I rev match every year change.
If your car has done 40k miles, a preventative clutch replacement may save you a flywheel.