The spec for the truck is 5w20 so there is no reason for the 5w30 in the winter. In fact in the winter your better off with 0w20 particularly if it is going to be sitting quite a bit. I just changed my oil from the Amsoil 5w20 I usually run to the 0w20 even though a drive as much in the winter as I do in the summer.Truck most likely will not see much of the outside world (or salt) during the winter months. My 96 has now been downgraded to the daily driver. The 2500 will mostly be used for towing during the camping season. I will probably dump in 5w30 for the winter storage so its ready to go in a few long months.