Tire rotation or crossing is the practice of moving the wheels and tires of an automobile from one position to another, to ensure even tire wear. Even tire wear is desirable to extend the useful life of a set of tires.

The weight on the front and rear axles differ which causes uneven wear. With the majority of cars having the engine in front, the front tires typically bear more weight than the rear tires. Front-wheel drive vehicles have not only the engine but also the transaxle in front, adding to the weight differential. Moreover, additional stress is placed disproportionately on the front tires by braking. Thus, tire rotation needs to occur more frequently for front-wheel drive vehicles.

In addition to that, mechanical problems in the vehicle may cause uneven tire wear. Wheels misaligned with each other and/or with the vehicle's axis will tend to be dragged along by the other wheels, causing uneven wear in that tire. If the alignment is such that the vehicle tends to turn, the driver will correct by steering against the tendency. In effect the vehicle is constantly turning, causing uneven tire wear.

Car manufacturers will recommend tire rotation frequency and pattern. Depending on the specifics of the vehicle, tire rotation may be recommended every 10,000 km. 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, tTire rotation or crossing is the practice of moving the wheels and tires of an automobile from one position to another, to ensure even tire wear. Even tire wear is desirable to extend the useful life of a set of tires.

The weight on the front and rear axles differ which causes uneven wear. With the majority of cars having the engine in front, the front tires typically bear more weight than the rear tires. Front-wheel drive vehicles have not only the engine but also the transaxle in front, adding to the weight differential. Moreover, additional stress is placed disproportionately on the front tires by braking. Thus, tire rotation needs to occur more frequently for front-wheel drive vehicles.

In addition to that, mechanical problems in the vehicle may cause uneven tire wear. Wheels misaligned with each other and/or with the vehicle's axis will tend to be dragged along by the other wheels, causing uneven wear in that tire. If the alignment is such that the vehicle tends to turn, the driver will correct by steering against the tendency. In effect the vehicle is constantly turning, causing uneven tire wear.

Car manufacturers will recommend tire rotation frequency and pattern. Depending on the specifics of the vehicle, tire rotation may be recommended every 10,000 km. 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.

Paradoxically for maximum traction, the best tires should be kept on the rear wheels of the vehicle, whether it is front- or rear-wheel drive. The reason for this is that if the rear wheels lose grip before the front ones, an over-steer condition will occur, which is harder to control than the corresponding under-steer which will happen if a front wheel is lost. Click here for more info.