I have to say there is definitely something wrong with 24k from Michelin tires. I've never gotten only 24k from any "normal" tire - and Michelin are the best IMO; that excludes the factory Firestone tires on a new 89 Cougar and a set of Yokohama off road tires I shredded....off road.
The current Defenders on my 2500 have been on it for 42,000 miles and still look new and have 10/32 tread left (just measured out of curiousity). They would probably go 75-80k (since they came with 13.5 32nds new) but they won't.....I replace tires at 40-50k so it's about time for these to go.
The Michelin Premier LTX tires on my previous SUV had about 40k on them when I got rid of the vehicle and they looked as good as these...….