Surprisingly, camber does not have a huge role in tire wear.
The usual culprit for side to side variations in tire wear is toe.
When the tires have any positive or negative toe, they are literally scrubbing the pavement any time they are turning: /\ , \/.
The spec for toe is usually very little (the scrub adds stability, as well as traction), and any increase/decrease from the specification will cause noticeable tire wear.
Do you have pictures, or tread depth measurements?
Pending pictures or measurements, I'd recommend going somewhere that deals with race cars for the best knowledge/care. They will tell you if any parts need to be replaced prior to aligning it.
I’m fairly certain that I’ve figured out what happened, it has nothing to do with my alignment. I was driving with low tire pressure in my rear tires for a time without knowing it.
The two center Wear Bar sections showed a fair amount of tread left, they were not worn to the Wear Bars. But both outer sections were worn through the Wear Bars. I drove my car from Dallas to Tampa, then to San Francisco, then to New Orleans and Biloxi, and then back to Dallas over a few months time. I bought new front tires while in Tampa and my old tires showed perfect wear. Somehow it appears that during the trips my rear tires had low pressure, even though I had the pressure checked before leaving Dallas and again during my return. What I didn’t know was that it takes three (3) hours for tires to cool, I was allowing 20-30 minutes. I don’t know how low or how it could have happened, maybe the temperature changes during the trips, or the tires weren’t completely cool when the pressure was checked. I adjust the pressure with each season change.
Now, when I went to buy new rear tires it appeared that the outer edge of the tires wasn’t touching the ground, and both the inner and outer sections had much more wear than the two center sections. It looked very strange that the outer sections weren’t touching the ground! But after putting a level on all four new tires I can see that they have the same alignment, and the outer edges of the new tires are definitely making contact with the road. I have a DIY camber tool ($14 on Amazon) arriving tomorrow to double check.
