Only replace rear tires BMW xdrive?

2017-11-15 16:24:50

I'm running a BMW X1 AWD Xdrive with OEM 19" wheel spec staggered:

255 / 35 / 19 Rear

225 / 40 / 19 Front

Staggered tires height difference is -0.06" (approx 2/32", back tires have less height, I used https://www.discounttiredirect.com/learn/tire-size-calculator)

Tires are BFG G-force comp 2 A/S. When new, they are ~ 9/32, they have less than 10k miles.

I noticed that my rear tires wear in the middle is already 6/32 and ~7/32 on the sides.

Front tires wear is 8/32 (!!) and a bit more than 7/32 on the sides.

It's my understanding that BMW cars are rear wheels bias, so even with Xdrive/AWD, the rear almost always wear first, specially in the center (due to quick acceleration and spirited driving).

QUESTION:

Should I keep running these until rear tires are 2/32 and change all 4, or I should change my rear tires already? I know that it's generally recommended to change all 4 tires on AWD, but since my front tires are almost new, and that that the rear is already -.06"