Tire rotation or rotating tires is the practice of moving automobile wheels and tires from one position on the car to another, to ensure even tire wear. Tire wear becomes uneven for any number of reasons. Even tire wear is necessary to maintain consistent performance in the vehicle and to extend the overall life of a set of tires.
By design, the weight on the front and rear axles of your car is different, which causes uneven wear. With most cars being front-engine cars, the front axle usually carries the majority of the weight. For rear-wheel drive vehicles, the weight distribution between front and back is near 50:50. Front-wheel drive vehicles also have the differential in front, adding to the weight, with a typical weight distribution of no better than 60:40. The result of this is that the front tires wear out at almost twice the rate of the rear tires, particularly when you factor in the included stress that braking adds to the front tires. Therefore, tire rotation for front-wheel drive vehicles is even more of a necessity.
Turning your car (which is unavoidable) also contributes to uneven wear. The outside, front tire is worn disproportionately. In right-hand traffic countries, the left front tire wears faster than the right front. Also, right turns are tighter than left turns, causing more tire wear. On the other hand, the sidewalls on the right tire tend to be more often bumped and rubbed against the curb while parking the vehicle, causing asymmetric sidewall wear. As would be expected, the exact opposite occurs in countries that drive on the left-hand side of the road.
Mechanical issues in the vehicle may also cause uneven tire wear. The wheels need to not only be aligned with each other but also with the vehicle. The wheel that is out of alignment will tend to be pulled along by the other wheels, causing uneven wear in that tire. If the alignment is such that the vehicle pulls to one side or the other, the driver will correct it by steering against the pull. Essentially, the vehicle is constantly turning, in this case, causing uneven tire wear. Additionally, if a tire is under or over-inflated, then it will wear differently than the other tires on the vehicle. Rotating will not help in this case and the inflation needs to be corrected.
Automobile manufacturers recommend tire rotation frequency and pattern. Depending on the vehicle, tire rotation may be recommended every 8,000 miles. The rotation pattern is typically moving the back wheels to the front, and the front to the back, but crossing them when moving to the back. If the tires are unidirectional, the rotation can only be rotated front to back on the same side of the vehicle to preserve the rotational direction of the tires. Most unidirectional tires can be moved from side to side if they are remounted.
The current school of thought recommends keeping the best tires on the rear wheels of the vehicle, whether it is front, or rear-wheel drive. The logic is that, if the rear wheels lose grip before the front wheels, an “oversteer” situation will occur, which is harder to control than an “understeer” situation. The intuitive idea that the front steering/driving tires need to be the best quality is not actually the case.
Tire wear becomes uneven for any number of reasons. Even tire wear is necessary to maintain consistent performance in the vehicle and to extend the overall life of a set of tires. Tire rotation or rotating tires is the practice of moving automobile wheels and tires from one position on the car to another, to ensure even tire wear.