ive wondered if with the X drive, if you disengage the connector to the motor that engages the clutch pack on the transfer case would you in-fact then have rear wheel drive only, i guess you might get some check lights on the dash.

i know with my Jeep Cherokee there is quite a marked difference in fuel economy between rear wheel drive and all wheel drive

just a thought, and especially if the gear that works the cam was to die then the car would still be drivable