polyurethane is squishy plastic, a bit like your food packaging.

They do not last longer than rubber, and can wear quicker if too much stress is given. Unlike rubber they do not harden so you do not get vibrations over time, but isnt as good as rubber at absorbing vibrations. Therefore it wears based on how much force is given to it vs rubber which wears from age instead of use for this case.

Theres a reason why the region of force where an object deforms permanently is called the plastic zone.

So can consider for lighter engines or more balanced engines that you rarely drive.