We are required to carry chains and WA and it is possible that the state patrol can even require AWD to use them, though rare. I just recently got my Tribeca and read that you can only use special chains. It indicates to get Subaru manufactured chains. I called Subaru up and they don't make any. Then the Service department told me that if you need to chain, that all four should. After reading the manual, it indicates to only do the front.
There is a lot of misinformation and I am hoping to get help from this newsgroup. Please let me know what chains can be used with a Tribeca, good place to get them and the proper usage.