[TechnoViking]

No two tires will ever be the exact same circumference. Brand new sets of tires are not the exact same circumference.

Tires are manufactured to be within a tolerance of the same circumference, and they start wearing unevenly as soon as you drive them.

I buy used tires on eBay and Craigslist all the time. Look for tread wear that is close to what you need to "match".

Bollocks to the tire salesmen who say you need to buy in matched sets.