It is NOT camber that eats up the inner portion of the tire. Excessive toe is your problem. I guarantee you that you are running too much toe in the rear. Go with no more than 1mm of toe in per side in the rear and you'll be fine. I run -2.3 deg camber in front along with -2.1 deg rear camber. My toe is 0 in the front and 0.8mm per side in the rear. Tire wear is very even.

You could run 0 camber and still get horrible wear if you have too much toe in.

 

What is the effect on feel or dynamics when other than 0* toe is run in the rear? Any disadvantage to running 0 toe in rear? I know what it does in the front.

 

DO NOT DO THIS. It's pretty dangerous. Your car will be very unstable under braking (especially if you have an open diff) and will want to snap oversteer when trail braking. The 911 has a lot of weight over the rear axle. You definitely want some toe-in in the rear for stability. 1.5-2.0mm total toe in the rear is a good compromise and is quite a bit less than the factory set up.

 

But how long do your tires last with those specs is the question...?

 

I get about 500 miles on a set at the track but wear is very even across the tread. Over the last 2 years I put about 4k street miles on a set of PS2s and they looked to have about 70% tread left. Wear was even. I don't drive my car very hard on the street though.

 

I've never gotten more than 5-6K out of a set of rears...I'm tempted to go back to 18's just for cheaper tire prices given the amount of miles I put on it.

 

I am shocked at people getting 4-5Kmiles on their rears. I was complaining at 15K on Michelin PS2s (inside chords showing, outside still about 3/32" thread).

I didn't check camber yet but my toe in is 0.42 deg total which I believe is in the GT2 spec range?

 

I would like to echo that toe is your issue. And also depending on miles likely rear control arms too if they are original. Blown control arms will cause your rear alignment to move all over the place and will eat tires. If your car is lowered, invest in adjustable toe links. Take your car to a shop and get your rear control arms check when you get aligned. Trust me, you would be surprised how many people are driving with worn out sloppy control arms that don't even know.

 

Monoballs and solid thrust arm bushing in your rear LCA will drastically improve your rear tire wear. The rubber bushings have a ton of flex which allow toe to wander all over the place = tire wear.. I run 15' to toe per side (0.5º total) and tire wear is dead even across the tire.

 

Those monoballs are pretty pricey for what they are. Would I be good with just toe arms and thrust arm bushings? I am lowered on H&R street coilovers.

 

For street driving yes. Make sure the toe arms are adjustable. You can even make your own pretty cheap.

 

Where would you go about sourcing parts for the toe arms?

 

would you please tell if 0 camber is possible with OEM arms and what toe do you run for better traction(street roll race)

 

Compromising performance handling to save some money on tires doesn't feel like a very good trade to me (and it becomes a safety issue). If this is your thought process, might as well detune the turbo then you won't break the rear tires loose and you'll save more money.

 

I'll give an update. I bought the parts that was suggested above for the lcas and the tire wear has vastly improved. Monoballs and solid bushings. Huge. I noticed it still gets a bit more wear on the inside edge, but it goes across the tire. Not quite all the way across though. I'll post a picture.