Originally Posted by 2therock
I'm wondering what the problem is with a FWD in crossing the drive tires to the back and bringing the rear tires forward.
Sorry for the stubbornness, but I just want to know the engineers reasoning.
Appears they want the "drive tires" from the opposite corner during rotation. That's a better rotation than the non drive tires get, but then again most wear is on the drive tires so they should get some special consideration. Each rotation then keeps the tires moving around real good that way. It takes 4 rotations for a tire to be back where it started from.
If one did an X rotation, then at the next rotation the tires would be at the spots where they were the time before.
The criss cross is on the drive tires so they get the benefit of a bigger switch over. Non drive tires tend to go along for the ride.
Nothing is cast in stone though, and tires can be rotated based on wear characteristics. If a rear tire has been running low on air for awhile, it may show more wear than the other tires. Doesn't make sense to move it to the front as that won't balance the wear out.
Okay, the answer to your question may be this:
Modern radial tires can - and should - be cross rotated. The theory behind the FWD / RWD difference is that when a tire comes off a drive position, it will have a little heel and toe wear. This type of wear can be noisy if the direction of travel is reversed. Keeping the tire on the same side will cause the heel and toe wear to gradually wear away, so that when it is cross rotated, the wear pattern will not cause a noise - or at least minimize it.