Done every 5,000 miles or so, a tire rotation is the act of moving tires around the vehicle so they have the opportunity to wear evenly. Some vehicles use “staggered” tire sizes meaning the fronts are smaller than the rears. In this case, they can only be rotated from left to right (and vice versa).  Some high-performance tires shouldn’t be rotated at all, since they’re made to turn in one direction only (usually indicated by an arrow on the tire’s sidewall). As always, consult your owner’s manual for more information. Mounting new tires or rotating existing ones doesn’t always result in a smooth ride. Because of manufacturing and mounting irregularities, tires need to be balanced by adding counter-balancing weights to certain parts of the wheel.