OK, we'll answer 3 questions here.1) What oil are you using in your Turbo diesel truck? 2)Are you satisfied with your oil of choice? 3) If you do switch, what will be your next flavor? I'll go first. 1) Amsoil Series 3000 5w30 2)I'll tell you in a week when my UOA comes back. My truck runs good and mileage is good, oil is very pricey even at my cost. 3) I have got my eye on a batch of Shaeffer Supreme 7000 blend, even the bottle looks cool.