[DistantTea]

Do our cars eat fronts or rears faster with xdrive?

I had to replace my rears and the fronts have 10k miles. Wondering if I should swap those.

[Ron Jeffries]

i always replace all four, but i'm weird.

[Maynard]

With x drive you are supposed to replace them all as a set, unless you get a shaved down one for replacing a flat. I can't say if it is truly necessary, but I was told this is standard info. Apparently the mismatch in diameters front-rear will put constant strain on the transfer case. Since the stock staggered ones aren't exact, it can tolerate some amount of discrepancy.

In general, the answer to your Q is that if you do a lot of turning hard, you'll eat fronts more than rears (outside edges). That has been my experience, but it didn't really show badly until I tracked it. You'd need to ask somebody who drag races but I think it is harder to really abuse an X-drive in acceleration, and wear would be more even depending on if you can break all 4 loose, or just one end (that's where the wear comes). These cars are fairly sensitive to alignment issues, and mine comes out of alignment over a year or so of potholes and rumble strips; this is probably more of an issue for tire wear than anything else unless you are tracking.

[DaleHeinz]

I have a square set up, so I rotate every 10K with my service intervals. I get about 40-45K our of my Michelin Pilot Sport A/S3+. I find my rears tend to take a bit more wear than the fronts. When driving with some spirit, I will throttle out of the apex and being a rear wheel drive bias AWD system, the rear tires tend to take more wear. Not much, but definitely noticeable between rotations.

[DistantTea]

I was going to replace all four but the dealer assured me that it wasn't an issue with such a minor variation. I'm square with AS3+s as well.