[riverdroid]

There might be some software issues at play with some modern AWD systems that I am not aware of, but it's traditionally a mechanical issue with 4WD and AWD. 4WD has a physical link, so having two different diameters linked stresses the links and tears the rubber. With AWD there is a differential, and different diameters cause mechanical stress and wear in a mechanical diff.

[jakear]

My understanding is that AWD has computer controlled power distribution and 4WD has a diff. My 4WD has a (lockable) center diff.

[centimeter]

Not quite: AWD has diffs between each of (FR,FL), (RR,RL), (F,R).

4WD has diffs between (FR,FL) and (RR,RL), but it has a transfer case (like a permanently locked center diff) between F and R.

So you’re not supposed to use 4WD on dry asphalt roads because the natural slippage between front and rear has no easy way to release itself.

Modern diffs are usually limited slip, which helps prevent spinning tires. LSD can either be mechanical or computer controlled. Computer controlled LSD can apply brakes to individual tires.

[jakear]

Interesting. So I think I technically have AWD, but I do have a transfer case with a 2X reduction available and a locking center diff.