I just got home from the Tire Rack and had my summer wheels re-balanced(had them foe 3 yrs and thought I'd have them checked before this summer)and the guy said that the inner side of all 4 tires showed some cupping or feathering. I have the a-spec suspenion(my car is an 04TL) and have had an alignment done each spring.The tires are Yokohama AVS db2's.My car has but 16K on the clock and my summer tires have about 12-13K of that. I've searched the forum and found some info that leaves me asking more questions than before. Also I don't know how to read the alignment numbers especially the toe because my sheet shows all numbers in degrees,while the TSB shows toe in millimeters. I don't have a fax machine,but here are the numbers that my car. Hopefully someone in the know can tell me if my numbers(degrees)are OK or should I get another alignment(BTW,I have used the same body shop each time for the alignment).

Front left camber (actual) -.04degrees

Front right camber (actual) -.05degrees

Front left toe (actual) 0.01degrees

Front right toe (actual) 0.00degrees

Front left caster (actual) 3.0degrees

Front right caster (actual) 3.2degrees

Rear left camber (actual) -1.3degrees

Rear right camber (actual) -1.5degrees

Rear left toe (actual) 0.08degrees

Rear right toe (actual) 0.06degrees

these are after numbers(degrees) not before. Thanks for any info.

 

those numbers are fine- you want about a degree neg camber for enhanced turn in response on cornering, and the car being lower than the stock ones does that for you.
the toe should come out close to zero- which you are, thats the in/out of the front of the tire.
It should drive straight like it is
Cupping can be a pressure issue since the camber is ok
Are your shocks leaking oil from the seal? that would cause cupping but not on all the tires
how was the toe before alignment- thats the real answer

Yokes arer not long life tires- they are sticky though!
Front wheel drive cars with 70 percent of the braking force and 60 percent of the weight on the front tires- they are subject to wear
20k miles from sport tires is good

 

Thanks for the quick reply. I was hoping to get around 30K with these tires,but maybe I was a bit optimistic. I keep 35psi all around...maybe I should rotate them more frequently. Shocks are not leaking. Toe before was: 0.18(left rear), 0.06(right rear).

 

ahh you had a prior toe issue- that'll wear the tires funky
You bought a sports car with the lowering package- face it- sports cars eat tires
Get good ones and enjoy

Personally I dont rotate tires. The change of their position causes its own internal tire changes, and over the life of the tire- the cost, or personal time spent on rotations, doesnt merit it. BMW now says its not worth it on their cars~