For moving from a dead stop, why is 4WD better than AWD (assuming equal tires)? Does it have to do with the locking differential, or something else...?
My understanding is that AWD systems generally allocate power to a wheel under certain conditions where it's detected that traction is lost. 4WD sends power to all wheels all the time, except perhaps when traction is lost to one wheel and there is no locking differential. I imagine 4WD feels more powerful at getting unstuck because all the power is there right away and you're not depending on a system / sensor to recognize the need for more traction before it's delivered.