Excessive tire wear

My daughter-in-law has a 2014 XC90 (3.2 R-Design). My son is having to put a 3rd set of tires on it after only 46,500 miles. The tires are wearing evenly and are rotated regularly. The last set (Pirelli) only has 28,000 miles on them and are needing to be replaced. Has anyone else seen this abnormal tire wear?

First, a 6 year-old car with only 47K on it means that there's a lot of city driving - ie. Lots of turns per mile. Most tire wear occurs in the cornering mode, while straight ahead driving is practically free.

Second, if the tires are OE (Original Equipment) - that is, the identical tire that came on the vehicle from the factory, even if they were bought at a dealership - those tires are likely NOT to wear well, because they were designed to the vehicle manufacturer's specs which includes tight rolling resistance requirements and they get that by sacrificing wear and/or traction, especially wet traction.

Third, you didn't tell us what the UTQG treadwear rating was, but what is needed is the highest treadwear rating - the first number in the rating. Read about UTQG ratings here: https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=48

I like Michelins. They are pricey but have a good tread life.

CapriRacer Very perceptive. Yes, the car is exclusively used for city driving. Again, thanks for your informative reply!