I went in for (inexpensive) tire rotation & balancing. Tech said they can't do it because my tires are un-safe: badly worn fron tires & dry rot on all four tires--so all four need to be replaced. The tires are only 3 years old, with 35,000 miles; car kept garaged (not exposed to sun damage). My personal observations were confirmed by experienced auto mechanics: NO worrisome wear on front tires, NO "dry rot" on tires; alignment MAYBE needed after rotation & balancing.