Do directional tyres need less tyre rotation than non-directional?

Question

A few years back, I've been told by a tyre salesmen that directional tyres need rotation more often than non-directional ones, like every 5k miles or sooner, since they can only go back and forth, so you must make sure they have more even wear, since you can't switch left-to-right. (Mind you, it was at an America's Tire, that does tyre rotation free of charge.)

However, as per discussion at Does more frequent tyre rotation make tyres last any longer?, it would appear that such uneven-axle-wear property -- that you can't really do much about differential imperfection -- would actually appear to make the frequent rotation more useful to non-directional tyres, since you'd probably want each tyre to travel on each wheel during its lifetime equally, whereas on directional tyres nothing like that is possible.

As such, it would seem like in perfect conditions, at least 3 rotations are warranted for non-directional tyres, and at least 1 for directional ones.

I would guesstimate that in practice, since it's difficult to predict how long the tyres will last, and the cycle with directional is so much shorter than with non-directional -- only 1 vs. 3 -- that directional tyres warranted to 60k really have no purpose being rotated prior to 15k to 20k, unless you really expect to get fewer than 30k or 40k miles out of it, respectively, whereas it's the non-directional ones that would benefit from the less-than-6k mile rotation the most.

Does this make sense, or am I missing something?

Answer 1

Whether using directional or non-directional makes no difference in how a tire should wear nor its rotation schedule. The reason why is, it's the tread which makes it directional or non-directional, not the core of the tire, nor the rubber which is used.

On Tirerack.com, they state:

A directional (also called a unidirectional) tread pattern is designed to roll in only one direction. It incorporates lateral grooves on both sides of the tire's centerline that point in the same direction and result in v-shaped tread blocks. These grooves enhance hydroplaning resistance at high speeds by pumping water more efficiently through the tread pattern. Unless they are dismounted and remounted on their wheels to accommodate use on the other side of the vehicle, directional tires are to be used on one side of the vehicle and are intended to be rotated from the front axle to the rear axle. If different tire sizes are used on the front vs. rear axle, the tires become location-specific and prohibit tire rotation unless remounted.

(Emphasis mine.)

The only other thing which is going to affect the longevity of a tire is how the tire is used. If the tire is a soft compound tire and is driven hard, it will wear out faster. If it is a hard compound tire and is only driven on the highway, it's going to last longer. In this case, increasing/decreasing the rotation schedule may have an affect on it's longevity.

With that said, using the rotation schedule provided by the manufacturer will provide the best longevity for the tire. It should be based on how the tire is built, its compound, load range, and speed rating. Every manufacturer is going to set their rotation schedule based on what they believe there tires need, so there probably is nothing corresponding between them.