At 96,000, put 2 non-rated new tires on 2/12 & had 2 of same tire put on 6/12 at on 2007 Cadillac STS

101,750 miles. In past year, I've had 4 alighments & now all 4 tires are almost balled on outside edge of each tire(rotations done w/oil changes) rest of tires look great. Shocks seem fine, ride smooth, & got 70000+ on original rated tires. Before I buy 4 new tires, what should I have done to fix alignment issues? Have 115,000 now.

Asked by for the 2007 Cadillac STS
have frt end inspected by a good frt end shop,then do necessary repairs with alignment