Maximum tread depth differential front/rear for AWD?

[PeriSoft]

Hey,

I've got a '15 3.8 AWD on which I've been running Vredestein Quattracs. I miffed my tire rotation last spring and wore a pair of them down more than I expected to, so rotated front-to-back and planned on replacing two this fall to keep things relatively even. However, the wear on the two better ones has been more than I expected too (grr), so I'm concerned about the tread depth differential between those and the new tires.

Does anyone know the stated max tread depth difference between front and rear tires? The manual doesn't seem to say anything and a search here hasn't turned anything up; other manufacturers seem to have significantly different tolerances for differential so I'd like to know for sure!

 

[Suburbazine]

It’s AWD. It’s best to have the better tires on the front, the center diff has enough tolerance to handle a moderate difference in tires. That said, you’re supposed to replace 4 tires at a time.

 

[PatMan]

Popular Mechanics: Rear tires provide stability, and without stability, steering or braking on a wet or even damp surface might cause a spin. ... Whether you own a front-, rear- or all-wheel-drive car, truck, or SUV, the tires with the most tread go on the rear.

Tire Rack: When tires are replaced in pairs in situations like these, the new tires should always be installed on the rear axle and the partially worn tires moved to the front. New tires on the rear axle help the driver more easily maintain control on wet roads since deeper treaded tires are better at resisting hydroplaning.