It's often discussed that subaru for example has a very high performing all-wheel drive system. The Nissan GTR is another that comes to mind. While I've never heard others be specifically criticized, I never hear great things about Toyota's Matrix XRS 4WD system.
I know there is a center differential, it can be limited slip, locked, etc. But wouldn't most seasoned manufacturers be able to come to a similar optimal solution fairly easily? What makes Subaru in particular so much better than a similar size Toyota (impreza vs Matrix)?
Edit - it seems this is more opinionated than I expected. I guess a refined question would be:
What gives a given 4WD system a higher performance in a given test than another system? ie -
- The subaru crosstrek is very efficient for a 4WD car. Why is it more efficient than something else (can't come up with an example)?
- The Nissan GTR is incredibly high performing on a track. What gives it a track advantage?
- That car ferrari has where it's only 4WD for the first 4 gears did surprisingly well in the snow on top gear. Why doesn't a Honda 4WD perform as well?
- A jeep in 4-low will suffer horribly in a turn, but has very high "grip" and towing power. What gives a 4WD system more "grip"?