Hi guys, been contemplating something different with my next OCI in the 05 PSD. Many of you know how critical oil is in the 6.0 with the HEUI system. They shear a 40WT down to a 30WT in no time so ideally the less VII's the better right? Right now I have Valvoline Premium Blue 15W40 in her but it absolutely hates this oil! Rough starting and lopes for a few minutes as well as you can literally feel the "sluggishness" versus the 10W30 Rotella/Delo I usually run. Anyway, I'm in central florida, its getting very warm so no cold starts for me! We work the truck all summer with towing horses and hauling hay so I'm thinking about running a good HDEO monograde! What do you guys think? Good idea or bad? should I go with a 30WT or 40WT?? I figure without any VII's it should be very stable and not shear near as bad, right?