nc211

Those with the 21”’s - how are the tires holding up for you? We’re likely on the wear bar for the rear by 20k miles... Pirelli’s. Funny, no tread warranty with them. Michelin’s on deck for the replacements when ready.

our fronts are doing fine, which is a total head scratcher to me...

chassis

GLS has a history on the X166 platform for early rear tire wear, possibly also on the GL X164. MB specifies excessive amounts of rear camber and toe. MB also specifies inflation pressure that is far too low.

Alignment settings, tire compound and inflation pressure are the reasons for premature wear. It's risky to change alignment out of manufacturer's specs for safety (handling) reasons. Especially on the rear axle. Tire compound is your choice. Harder tires wear longer but are noisier and buzzier. Inflation pressure is up to you, limited by the max pressure printed on the sidewall by the tire manufacturer. Max inflation pressure (tire mfr specs, not MB specs) result in longer tire wear but slappier and harsher ride results.

MB's suspension and tire specifications result in a safe vehicle that drives like a sofa on wheels, the day it drives off the dealer lot. That's what they want. But it also results in very fast tire wear, and there are other ways to skin this cat, that MB chooses not to do.

mikapen

Are you looking at the wear bars all across the tread of front and rear tires? As @chassis said, there is a lot of camber on the rear, which improves handling but tends to wear the inside edge faster than you'd like. My solution will be to dismount the tires at about 10,000 miles, to switch the wear on the (former) inside of the tread.

Over-inflation will reduce tire life, reduce grip, make the tires less able to resist impact damage, and make the ride harsher. Not the solution.

Americans seem to rate their tires according to tread life, but I (also American) tend to rate my tires by traction and other tire-like things like hydroplane resistance. I don't expect my tires to reach 30,000 miles. I change out at 4 to 5/32".
I shun tires with high tread life warranties because they have always let me down in the things I value in a tire.

However tire and rubber technology has changed a lot in the last four or five years, and some high-tread-life tires may also stick to the road. That would be nice.
I'm waiting for these "modern" tires to be manufactured in our sizes.

nc211

Yep wear bars all across the tire surface. They’re wearing evenly, just quickly. I knew they wouldn’t last, read those comments on the previous version on rear tire wear. No biggie, not terribly upset and knew what I was buying. The funny thing is Michelin’s offer a tread warranty, which given how fast the MB eats the rear tires, is surprising to me they would do that on a primacy tire, which I really like in general for tires. Probably my favorite. And cheaper too when compared to the Pirelli’s. Makes sense to go that route next. They wear too fast, claim warranty support. You can’t rotate these tires in the staggered 21” setup. They are what they are, and by design of the car, not meant to be moved around. So, Michelin clearly must know that too...

the front tires are doing far better than the rear. Probably 65% tread life left, where as the rear is probably at 20% to wear bars.