+1 - they are disengaged unless 4WD is active.
Originally Posted by hatt
These trucks(or most of them) disengage the front driveline when in 2wd via vacuum operated hubs.
Originally Posted by meep
I'd run syn in the front as well - ideally for thinner cold weather characteristics. It's a waste to spin all that stuff when just needing RWD. I *really* wish there was a manual hub offering for these things so we could disconnect the front driveline unless we actually need it. It gained me 1 mpg in past on a pathfinder.