Been running the signature series 5w-40 in my dads 2015 ecodiesel and my 2016 Cummins and love it. About to order more and I see they have a 0w-40 now. Just curious if anyone is running the 0w-40 and how they like it, as it does meet the specs for the two engines. I like the thought of the 0w for when snowmobiling and the trucks sitting in -15 for a few days with no place to plug in. I heard though with such a large gap between the weights, that the 40w is actually a little less, any truth to this?