mim3

Cleaning the car today. The right rear tire is severely worn "cupped" on the inside. Looks like new tire and alignment is in order.

This happened very quickly...any ideas what is out of whack?

mim3

Another pic.....

roberga

low pressure

teflon_jones

i'd suspect low tire pressure too. other possible causes are bad toe-in on that wheel, or (more severe), a bent rear suspension crossmember.

Scouser

You mean "two" new tyres

Keyvan

Well i thought that was normal (what the dealer said)..cause all Porsches come from the factory with toe in setup to reduce oversteer.

Mine look like that too. Got about 7000 miles

Gretch

aaaaaalingment..............is off. If it was tire pressure both edges would be worn...............

I have had tires that looked like that...........alignment. period.

mim3

Thanks everyone. I've been running rear tire pressure at 42psi which my mechanic says is 2psi to low. The left rear looks fine and the fronts look new. Car has 14k miles on it.

Do I really have to replace both rears? I do know the new tire diameter will be slightly greater (if I assume good manufacturing QC). Is that the only issue?

Not overly impressed with the Conti's. But don't want to replace 3 good tires.

Comments Please....

adsc4s

Not sure of 996's but many 993's run 34 front and 36 rear, even though Porsche recommends 44.

mim3

I know...everyone has a different pressure recommendation.

Hard to belive 2psi could cause this so quickly. I tend to think it is out of alignment.

Now I have to decide whether or not to get the PSS9's.

Carlos from Spain

I always run 2 PSI or more lower than recommended especially in the rear (how much lower depends on the tire make-model I'm using, the PS2's I'm using now work better with more pressure than others, but still bellow rec), anyway, I still never had that happen, thats BS.

Besides, if that would of been the cause, the other rear would look the same. Its either significant underinflation compared to the other rear or alignment. I had that happen once and in my case it was due to a slow leak puncture that caused underinflation over a long highway trip.

Gery NJ

I think rears wear out unevenly, compared to the fronts. But never the less u should check aligment and I would spring for new both tires.
My Conti's lasted about 10K.