Does more frequent tyre rotation make tyres last any longer?

Question

Say, one gets new directional tyres that are warranted to 60k miles and have 11/32" of tread when new.

If one rotates them at 20k miles (if directional; otherwise, at 10k, 20k and 30k, if non-directional and using a cross rotation), and then finds out at 40k miles that all four have reached their end of life -- 2/32" of tread left (or, alternatively, some at 2/32", others at 3/32") -- would that generally be a warrantable condition, or could the less frequent tyre rotation as above really shorten the life of the tyres by so much?

I don't see how less frequent rotation should realistically shorten the life of a tyre set by so much -- the whole purpose of rotation is to make sure the tyres wear out evenly, so you run a better luck of having to replace all of them at once, having better handling overall.

Is the above line of thought considered wrong? If so, does the other side have any proof to back up their claim?

After all, each mile gets that many nm of tread from front and rear axles each (or, as pointed out in one of the answers, from each individual tyre, due to differential imperfections), what difference does the rotation make to the total nm of tread eaten out by each mile from the set overall?

Answer 1

Regarding the warranty, the warranty would cover what it clearly states it will cover. I can't really answer that question.

Regarding even tire wire and rotating as a strategy to achieve even wear across the tires, I'll try.

In most vehicles on the road today, there is one power wheel. On my Toyota Tacoma it's the right rear. It wears faster as most of the power is passing through it to drive the the vehicle forward. As such, it wears faster. As does the front right on a Honda Civic, I believe. Nonetheless, rotating the power wheel is a great idea. It's an effective strategy to get the tires to wear out at the same time. If you don't do it, they won't wear evenly and you will be replacing tires one or a pair at a time.

Answer 2

Whilst the math in the question might make sense, with the front-wheel-drive cars, it would go in violation of the established practice of having the better-handling tyres on the rear axle in order to combat oversteer.

Tire Tech Information - Where to Install New Pairs of Tires?

As such, if rotation is delayed to 20k miles of a 60k mile tyre, and especially if it's expected to last only 40k in total given the driving patterns etc, you effectively end up putting the new tyres to the front, and switching the half-worn tyres from the front to the rear, compromising the driving experience.

It can thus be argued that in the interest of safety with front-wheel cars, it is NOT a good idea to start rotating the tyres from front to back past half of their useful life-span (rotating non-unidirectional tyres from left-to-right once would still be a good idea and at least a tiny bit useful), which would then surely void the warranty as it'll be impossible for the tyres to achieve even wear.

Plus, unless you want to continue with such practice, you'd have to throw the whole set out, since buying just a single pair would place it in the rear, going quite close to repeating the cycle (although I guess the new pair will only worn out ~1/4th when the rear pair from the first set worms out 100% on the front, since it'll be starting at ~1/2 when the original front pair will be gone).