New to the board, wanted to say hello to all. On the valvoline website, I put in my vehicle make and model (03 ram 4.7, 60k) They recommend 10w30 for my truck. Others, including the manual, recommend 5w30. Why would they do that? I could understand over 75k, but living in ny, where it plummets below 0 at times, I found there results suprising. Maybe 10w30 would be a good idea for oil consumption problems, or towing (which I do not do). My question is, do you think there was testing on these engines to verify there result? I'm another member here who would have sleepless nights thinking about oil, viscosity change in my rides.