4WD vs. AWD whats the difference?

4WD is locked at the transfer case and thus is best used only in low traction conditions. Steering will become more difficult if you were to be on dry pavement in 4WD because the front and rear axles travel different arcs and will cause binding. AWD, on the other hand will split power between the front and rear axles, but will allow slippage, usually through something like a viscous coupler. My older Jeep Grand Cherokee had a NV242 transfer case that allowed AWD for driving on the road, as well as a 4WD position for off road. If you drive on the road only, an AWD system is the best answer, as you don't need to remember to shift it in and out of 4WD as conditions require. If you want to take the vehicle off roading, you want something designed around 4WD capability, like my Jeep Wrangler.