Anyone ever tried this stuff? I can get a decent deal on a case through work but never ran a 5w50 before. Currently running Mobil1 15w50 in my truck. Mild 360 doing a lot of towing and off roading. Like the 50weight after the engine temp gets up there, but thinking that 5w50 might be a good oil when she weather cools off. Looking at their website, it's a full synthetic, with high zinc level for flat tappet cams. Anyone have any thoughts or used Schaefer oil?