Just wanted to share with everyone. I have M030 Suspension and Michelin Pilot Sport PS2's which are not cheap. Alignment is checked once a year and was within spec. Tires have less than 5000 miles on them and are wore out on the inside due to camber....

Looking at installing rear adjustable toe links and trying to dial some of the camber out for longer life. A little expensive when you have to replace rear tires every 5000 miles.

 

That is premature wear. You should get 7,500 - 10,000 miles on a set of rear tires.

 

Something is definitely out of alignment.

 

Camber may not be the only issue, check the "toe out." Since they are unidirectional you could remove the tires and swithc sides, this would put the now current outsides inside.

 

This isn't always a good idea. Some unidirectional tires are asymmetric. They tread compound varies between the inner and outer shoulders of the tire. This can cause unpredictable or reduced handling characteristics.

 

Definitely have the toe checked. Off-spec toe combined with (proper) negative camber will chew up PS2s quickly. Don't ask me how I know...

A good alignment on a 996 isn't cheap (have a proper shop do it) but it pays out quickly in terms of much better tire wear.

 

Alignment is checked once a year and is dead on!

 

You said it was within spec, now you say it is dead on. The only way for you to know which you have is to obtain a before & after printout of the actual alignment settings. Also the photo you posted of a tire is not a PS2, it is a cheaper, allseason tire, which is more vulnerable to uneven treadwear than a PS2.

 

The tire is the Pilot Sport AS+. It's a directional tire, not asymmetric like a PS2 is. Directional tires can usually be flipped from side to side. It's not a good idea to flip an asymmetric tire because of the possible tread compound change as you move across the tread cap.

 

Different shops have different ideas of what dead on means. You need a printout of what the settings are.

Some alignment techs like to dial in more toe as this is supposed to make the car feel better. What it does is it shortens the tire life.

When I have the car aligned I ask for the plain jane factory alignment numbers and insist the steering wheel be centered.

Afterwards, rear tire life can approach and in some cases pass 20K miles. This is true for both my cars.

Rear camber has zero effect on tire wear. One time with my Boxster's rear tires set with max. allowable camber tire wear (and car feel) was unaffected.

But let that toe get out a little and oh my tire life gets cut short.