2008 XC-90 non-turbo with 89858 miles.
Rotated my tire today and noted a minor abnormal wear pattern starting to develop. Tires are Nokian WRG3-SUV 235/65 R17 All Weather tires. Tires are 108H rated XL (speed rating 130 mph, 2200 lb. load). Tire pressure has been maintained at 36 psi. Tires have been on the vehicle for 13113 miles. They were rotated at 81369 (4624 miles after installation and again today (8489 miles since last rotation). Rotation is standard Volvo pattern of front to rear and rear to front, keeping left tires on left and right tires on right.
Now to the abnormal pattern: All tires looked good and showed no evidence of damage. The two tires removed from the front showed an abnormal wear pattern on the inside. Both had a sort of a cupping starting. Every eighth rib had more wear than the seven ribs between two worn ribs. The wear was minor and some of the cuttings in the rib were still evident and present. Otherwise the war pattern appears normal and even. The "6" and "4" cut into the center rib is still totally visible on all tires.
My question; because I am experiencing the same indication on each side I am ruling out alignment and wondering if I am starting to see the indications of weak struts or other front suspension issues.
Any thoughts or comments are appreciated.