a)equalize tire wear. B)increase fuel efficiency.
For the same reason I change condoms - to equalize the wear and reduce the likelihood of eventual breakage.
Definitely! Every few thousand miles you also need to change the air in the tyre as well - bit like an oil change, just less messy. Even a girl could do that! .....snigger......
Technically, it does both, but the main reason is ''a'' If you have a front-wheel-car for instance, you're going to have more vehicle weight on the front of the car, because you have the engine, trans, driveline all in the front. And since the drive wheels take more abuse anyway, all-the-more w/ a front driven vehicle. After it wears a fair amount, you'll notice the front tires are fairly worn and the rear ones are look almost new still. So yes, you're equalizing wear pretty much. : )
A -- Equalize tire wear, which also yields (b) which is to increase fuel efficiency. The front tires typically wear more, because they have to steer the car, do most of the braking and they have a more complex alignment. In modern front-wheel driven car, they also do the acceleration and they carry most of the car's weight. The wear is accelerated when driving in the city or in bendy roads, and when the driving style is not very gentle. Modern steel belted radial tires are more durable to tread wear, and to diagonal wear, so there is such a thing as rotating them too frequently, but this also depends on the tires' treadwear and brand. Tires will a lower treadwear will have a softer tread which will wear out sooner and require a more frequent rotation. Radial tires should be rotated where the front pair is switched with the rear pair, and without switching sides between left and right. Tire rotation should therefore take place between 20,000 to 30,000 kilometers of milleage, depending on those variables. If done carefully, it might extent tire milleage to about 80,000 kilometers overall.
