A friend of mine sells Amsoil, so for my oil change next week I'm going to buy from him. So I searched this wonderful site for a preferred oil weight... and found no straight answer. '03 9-5 V-6 w/flappy paddles. Some people said 5w-40, some said 0w-40. Some said same weight year round, others said to change it. Anyone want to offer input? Is there a difference in oil needs between the 6cyl and the 4cyl? Any other suggestions for weight?