If you have an all-wheel or four-wheel vehicle and a full size spare, it is best to rotate it with the four tire each rotation to keep tread wear even.
Because the front and rear tires of all-wheel drive and four-wheel drive vehicles perform different duties while accelerating, braking and cornering, tire rotation is important to even out, and maintain equivalent treadwear of all of the vehicle's tires to minimize potential driveline stresses.
If the vehicle is equipped with a matching road wheel and full-sized spare tire, they should be integrated into the vehicle's rotation pattern at the first tire rotation. This will allow all five of the vehicle's tires to share in the workload and wear at similar rates. In the event that a single tire is damaged and has to be removed from service, this will allow the tread depth equivalent spare tire to be used with the remaining three tires.
If the spare is not integrated into the vehicle's tire rotation pattern, it will not match the tread depth of the four worn tires on the ground when called into service. Additionally, if a single tire is replaced by the full size spare tire, hopefully the new replacement tire can remain as the spare tire until the other four tires have worn out and need to be replaced.
