Can someone tell me what the tread depth is on a new set of Michelin Pilot Sport PS2's is?

The set I have is 3.75 years old and has about 16k miles on it. (none track).

I'm trying to decide if I buy two new rear tires only or just replace all 4 at this time, based on the tread left in the front tires. (which are undamaged, just one rear tire has a sidewall bulge)

 

Go to TireRack.com and for your particular sized tire look under "specs". It has the info you are looking for. Best,

 

Thanks for the pointer.

For the 18's: 295/35ZR18 (99Y) SL N4(Porsche) it indicates 8.5 / 32nds of an inch.

The rear currently has 7.5 / 32nds of an inch still on it... so most of the tread is still there.
They are 3.5 years old and the car has 16k miles on it, BUT I only run them half the year with the other half having the winter tires on the car, so the tires have probably seen:
1.8 years and about 8,000 miles of road use. (but the rubber has a calendar age of about 3.8 years I think)

So at this point, I think I'll just replace the back two tires for now.