Tire rotation
Encyclopedia
Tire rotation or rotating tires is the practice of moving automobile
wheel
s and tire
s from one position on the car, to another, to ensure even tire wear. Tire wear is uneven for any number of reasons. Even tire wear is desirable 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 differs which causes uneven wear. With the majority of cars being front-engine cars, the front axle typically bears more of the weight. For rear wheel drive vehicles, the weight distribution between front and back approaches 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. This means, all else being equal, the front tires wear out at almost twice the rate of the rear wheels, especially when factoring the additional stress that braking puts on the front tires. Thus, tire rotation needs to occur more frequently for front-wheel drive vehicles.
Turning the vehicle will cause uneven tire wear. The outside, front tire is worn disproportionately. Cloverleaf interchange
s, and parking ramps turn right in left hand drive (otherwise known as right hand traffic) countries, causing the left front tire to be worn faster than the right front. Furthermore, right turns are tighter than left turns, also causing more tire wear. Conversely the sidewalls on the right tire tends to be bumped and rubbed against the curb while parking the vehicle, causing asymmetric sidewall wear. The symmetric opposite occurs in countries that drive on the left.
In addition, mechanical problems in the vehicle may cause uneven tire wear. The wheels need to be aligned with each other and the vehicle. The wheel that is out of alignment
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. Also, if a tire is under or over-inflated, 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.
Car manufacturers will recommend tire rotation frequency and pattern. Depending on the specifics of the vehicle, tire rotation may be recommended every 12,000 km (8,000 mi). 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; tires with asymmetric rims are a rare exception. More complex rotation patterns are required if the vehicle has a full-size spare tire that is part of the rotation, or if there are snow tires.
To clarify; the pattern for asymmetrical tires to be rotated, or positioned, is for the tires on the driving axle of two-wheel drive vehicles to remain on the same side of the vehicle as they are moved to the non-driving axle, and for the tires on the non-driving axle to cross over to the opposite side of the vehicle as they are placed onto the driving axle. For all-wheel drive (AWD) vehicles and four-wheel drive
(4WD) vehicles, it is recommended that the tires from each axle cross over as the fronts move to the rear and rears to the front. For the 4WD configuration, it is dependent upon how much 4WD driving is actually performed, whether it's controlled via mechanical/computerized devices or in vehicle controls, the recommendation will likely be found in the Owner/Operator manual or can be obtained by speaking to the manufacturer or dealership.
Current thinking stresses the desirability of keeping the best tires 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 oversteer condition will occur, which is harder to control than the corresponding understeer
which will happen if a front wheel is lost. This is also the case if a tire blows out, so the intuitive belief that the front steering/driving tires need to be the best quality is not actually the case.
In some cases (for example, BMW
), automobile manufacturers may recommend performing no tire rotation at all. Additionally, some vehicles are designed (or retrofitted) with front and rear wheels of different sizes and unidirectional rotation treads, making rotation impossible.
Automobile
An automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor...
wheel
Wheel
A wheel is a device that allows heavy objects to be moved easily through rotating on an axle through its center, facilitating movement or transportation while supporting a load, or performing labor in machines. Common examples found in transport applications. A wheel, together with an axle,...
s and tire
Tire
A tire or tyre is a ring-shaped covering that fits around a wheel rim to protect it and enable better vehicle performance by providing a flexible cushion that absorbs shock while keeping the wheel in close contact with the ground...
s from one position on the car, to another, to ensure even tire wear. Tire wear is uneven for any number of reasons. Even tire wear is desirable to maintain consistent performance
Performance
A performance, in performing arts, generally comprises an event in which a performer or group of performers behave in a particular way for another group of people, the audience. Choral music and ballet are examples. Usually the performers participate in rehearsals beforehand. Afterwards audience...
in the vehicle and to extend the overall life of a set of tires.
By design, the weight on the front and rear axles differs which causes uneven wear. With the majority of cars being front-engine cars, the front axle typically bears more of the weight. For rear wheel drive vehicles, the weight distribution between front and back approaches 50:50. Front wheel drive vehicles also have the differential
Differential (mechanics)
A differential is a device, usually, but not necessarily, employing gears, capable of transmitting torque and rotation through three shafts, almost always used in one of two ways: in one way, it receives one input and provides two outputs—this is found in most automobiles—and in the other way, it...
in front, adding to the weight, with a typical weight distribution of no better than 60:40. This means, all else being equal, the front tires wear out at almost twice the rate of the rear wheels, especially when factoring the additional stress that braking puts on the front tires. Thus, tire rotation needs to occur more frequently for front-wheel drive vehicles.
Turning the vehicle will cause uneven tire wear. The outside, front tire is worn disproportionately. Cloverleaf interchange
Cloverleaf interchange
A cloverleaf interchange is a two-level interchange in which left turns, reverse direction in left-driving regions, are handled by ramp roads...
s, and parking ramps turn right in left hand drive (otherwise known as right hand traffic) countries, causing the left front tire to be worn faster than the right front. Furthermore, right turns are tighter than left turns, also causing more tire wear. Conversely the sidewalls on the right tire tends to be bumped and rubbed against the curb while parking the vehicle, causing asymmetric sidewall wear. The symmetric opposite occurs in countries that drive on the left.
In addition, mechanical problems in the vehicle may cause uneven tire wear. The wheels need to be aligned with each other and the vehicle. The wheel that is out of alignment
Wheel alignment
Wheel alignment sometimes referred to as tracking, is part of standard automobile maintenance that consists of adjusting the angles of the wheels so that they are set to the car maker's specification. The purpose of these adjustments is to reduce tire wear, and to ensure that vehicle travel is...
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. Also, if a tire is under or over-inflated, 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.
Car manufacturers will recommend tire rotation frequency and pattern. Depending on the specifics of the vehicle, tire rotation may be recommended every 12,000 km (8,000 mi). 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; tires with asymmetric rims are a rare exception. More complex rotation patterns are required if the vehicle has a full-size spare tire that is part of the rotation, or if there are snow tires.
To clarify; the pattern for asymmetrical tires to be rotated, or positioned, is for the tires on the driving axle of two-wheel drive vehicles to remain on the same side of the vehicle as they are moved to the non-driving axle, and for the tires on the non-driving axle to cross over to the opposite side of the vehicle as they are placed onto the driving axle. For all-wheel drive (AWD) vehicles and four-wheel drive
Four-wheel drive
Four-wheel drive, 4WD, or 4×4 is a four-wheeled vehicle with a drivetrain that allows all four wheels to receive torque from the engine simultaneously...
(4WD) vehicles, it is recommended that the tires from each axle cross over as the fronts move to the rear and rears to the front. For the 4WD configuration, it is dependent upon how much 4WD driving is actually performed, whether it's controlled via mechanical/computerized devices or in vehicle controls, the recommendation will likely be found in the Owner/Operator manual or can be obtained by speaking to the manufacturer or dealership.
Current thinking stresses the desirability of keeping the best tires 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 oversteer condition will occur, which is harder to control than the corresponding understeer
Understeer
Understeer and oversteer are vehicle dynamics terms used to describe the sensitivity of a vehicle to steering. Simply put, oversteer is what occurs when a car turns by more than the amount commanded by the driver...
which will happen if a front wheel is lost. This is also the case if a tire blows out, so the intuitive belief that the front steering/driving tires need to be the best quality is not actually the case.
In some cases (for example, BMW
BMW
Bayerische Motoren Werke AG is a German automobile, motorcycle and engine manufacturing company founded in 1916. It also owns and produces the Mini marque, and is the parent company of Rolls-Royce Motor Cars. BMW produces motorcycles under BMW Motorrad and Husqvarna brands...
), automobile manufacturers may recommend performing no tire rotation at all. Additionally, some vehicles are designed (or retrofitted) with front and rear wheels of different sizes and unidirectional rotation treads, making rotation impossible.