I purchased by truck used at 13K miles. It now has 36K, I started my Blackstone analysis at 20K miles. With Rotella 15w40 and Blackstone seemed impressed by the numbers refer to my engine as "strong and healthy" engine. I did run Delo 10w30 this winter and saw a noticeable lowering of viscosity at 40c and 120c. The metals climb slightly. Went back to 15w40 Delo and all the metal numbers and viscosity beat all the previous. Not sure if the engine has broken in at 35K and is not shearing the oil as bad as earlier thought. I did run across Delvac on sale and will test the oil again when I hit 40K to compare against Rotella and Delo. Strange my mileage went up .5 to 1 mpg with Delvac maybe it is summer fuel. The engine does sound a bit quieter. Maybe I will try Ford's to round the field out.
Synopsis: I will stick with a dino 15w40 oil and change at 5K using only Ford
[Bfilters[/B], I will even run it during the winter with occasional trips to the Rockies with sub zero temps and plug in. If I see any metal numbers rise or viscosity falls I will drop back down to 4k oil changes. I am interested in seeing how the Delvac does. Oh, only pick those since they are the least expensive at Wal-Mart. Valvoline is only available at a local parts store at $5+ a gallon more(disqualified)
2010 F-350 Lariat CC LB 3.55 11,500 GVWR DPF/EGR delete RCD 450 tune