> That was an artifact of early US radial tire manufacture, which was
> generally piss-poor in quality. Some tires were prone to belt
> separation if the direction of rotation was reversed.
Not just US radial tires, early Michelin radials had the same problem. BTDT,
had a terrible time figuring out why the car rode like it had a flat tire, but
all the tires had air in them.
Even without reversal, carcass failure was a common problem with early radials
... the tread just lasted longer than the carcass (body) of the tire.
> Tires are better now. There's no reason to avoid changing the direction
> of rotation of tires.
I agree with John, modern tires don't seem to have a problem with reversing
rotation. Of course, I no longer buy "plain old all weather" tires, as I
consider high performance tires to be a safety feature.
But I still have a nagging suspicion that the main advantage of tire rotation is
that it gets you into the shop so they can try to sell you something.