Some low profile performance tires have a tendency to develop what's called a "heel and toe" wear pattern if they are not rotated every 5,000 to 8,000 miles. This is caused by tread flex and the belt design of the tires. If tires with this kind of wear tendency are not rotated, the tread may develop a washboard wear pattern that causes annoying vibrations and/or noise at speeds above about 40 mph. Once the wear pattern is established, it may be too late to reverse it by rotating the tires. Replacing the tires (and switching to a brand or design that is less "quirky") may be the only way to cure this kind of wear problem.