I am looking at picking up a used rav4 to take me to the mountain and get around when it snows. My question is.............. the way I understand the Rav4's 4 wheels drive system is that it normally operates only the front wheels (I know the 5 speed had a center diff lock..I'm referring to the auto) until slip is detected at which point torque is then progressively fed to the rear wheels until traction has returned. If so, then the system operated much like the CR-V. It would seem that, for instance, on a constant uphill grade, if the front tires don't quite have the traction, the vehicle will be in continuous cycle of feeding power to the rear tires until it hooks up then power is returned to the fronts....then traction is lost again and this goes on and on. Could someone shed some light on this?