Subaru Problems? Ask a Mechanic for Answers ASAP
Hello I will help you with your question,
With 36,000 on the "good" tires if you installed two new tires that would put then above the 3/8" maximum variation between the tires allowed so you would need to replace all 4. One of the unfortunate effects of having an all wheel drive vehicle.
Have you had it aligned? Did they give you the final specific readings with the repair order?
Every few years for the alignment unless you hit a hole and knock it out or you notice tire wear.
Did the dealer mention the tire wear in December?
It is only the one tire that wore or is it both front tires?