kmar, in the mile high pile of books you received when you picked up the RX is a brochure from the tire manufacturer. I'd refer to that as far as warranty. You didn't mention which brand you have. Some are better than others. We have the tire thread
with plenty of opinions. Also make sure the tire pressure is correct. Dealers like to overinflate which can affect wear. Have them check the alignment. You're entitled to one during the first year or 12,000 miles.