Originally Posted By: Merkava_4
In my very strong opinion, tire rotations are completely unnecessary. You got perfectly even wear on the back tires and then you move those tires up front where they are subject to uneven wear from being out of alignment. So now instead of having two good tires and two bad tires, all four tires are bad!
Ehh, thats sort of true, but only in cases where you're in a pickup truck or a mustang or something with a solid axle. Anything with independently rear suspension is going to wear tires differently.
In your example, lets use some arbitrary mileage numbers. 40k miles, your rear tires have 4-5/32 of tread, and your fronts are bald on the outside. You need new front tires. So, what do you do? Do you buy new front tires only? Then your rears will need to be replaced soon, and you'll have mis-matched tires. Not a big deal to some people, but if your concern is having good tires.... Do you move your 4-5/32 tires to the front and put the new tires on the rear? The tire shops advocate this, for the same reason automakers engineer understeer into their cars - it's not any safer, but the general public can't drive worth a [censored] and are terrified of oversteer - they'd rather understeer into a pole or ditch instead. And then in 10k miles you'll need new front tires again, what then? Move the fairly new rears to the front, and rinse:repeat?
Rotating tires lets you gain roughly even wear on all 4 tires, so that when it's time for new tires, you're replacing all 4. Maximizing traction and service life of all 4 tires. In the scenario above, if you got 40k out of the fronts and 50k out of the rears, you'd most likely get 45k out of the full set of rotated tires, and you'll have better traction all around.