So just how do you really test out the 4wd on a Rav4 ? I know you can push sedu lock diff button and it will put a certain amount of power to the rear until you hit the brakes or exceed 25 mph. How do you really know it works ? Up on the lift an strap it in and run it ? When we bought the Rav 4 new in December 2011. It was terrible in the snow we even took it back to the dealer and the service rep really did not understand how this system worked. The service Rep. Said you had to push the seudo lock diff button if you wanted 4wd. Kind of silly. The Toyoy A20 tires had quite a bit of release grease and the the Rav during the second winter worked well ? Perhaps something else is going on here. Sometimes new tires don't get their grip until 500 miles. Any thoughts ?