Keep in mind if you do have two sets of tires, you are going to get a lot more wear out of them. I generally get about 2-3 seasons out of my snow tires. My regular set lasts even longer since I am swapping them out. It's a bitch at the start to have them both, but in the long run it'll save you money and headaches if you are driving up in the mountains frequently. I can't tell you how many times my FWD vehicle has gotten through stuff where AWD and 4WD vehicles were plain stuck.