Edge wear is an alignment issue. The wheels are steering outward if its the inside edge. With the excessive edge wear it will have a wavy pattern or rippling on the edge. Alignment.
If the tire is choppy across the total contact patch, its a balance or strut issue.
A combination of edge wear and choppy patch is both.
Generally, the struts are worn out enough by 90-100k to justify replacement. KYB struts are strongly recommended since they respond excellent and have a long life. I am going on 125k on the set I have on my Cavalier and it still rides like I put them on yesterday. Every other vehicle I have installed a set on has been equivalent. Replacing them is a job though. The springs have to be compressed to swap the struts once the assembly is removed from the car. An alignment will be necessary when the struts are replaced, so may as well do both at the same.
Average cost for a full set of struts and alignment with me on one of these is about $11-1200 with the alignment. Calls for 6 hours labor to do all 4 and the struts run about $150 each.
It is both choppy (most noticeable on the studded snows, but still slightly present on the summer tires) and worn worse on the inside of the tires..
The car drives and stops fine though..
Maybe I can try a good 4 wheel alignment first, then see if it is still happening..
Tires are freaking expensive for this car too. I also need to replace a front axle shaft due to a torn boot, which generally needs an alignment afterwards... Maybe I'll tackle it all at once on a weekend and just rent a spring compressor. I have an old in ground lift at my farm shop... Are there any other special tools I need?