I have a new XC90 T8 Inscription coming in - the dealer ordered it with 21 inch wheels. The car has air suspension. My question is: do the 21" wheels have a harder ride? Does the tread last as long? Advantages vs disadvantages? I am more interested in the ride -- then the looks of the wheels. Should get them changed to the standard 20" wheels? Comments. I have looked at the other posts - but only 1 comment on the ride and none vis a vis tread wear.