Whose running it? Looking at running the 7000 15w-40. I know it's pretty expensive but is it worth the extra several bucks? I'm currently running Mystik 15w-50 by Citgo and it's been nothing but good for us here on the ranch since the 80s in all of our equipment. I know schaeffers has been around since 1839 and the people the run it swear by it. Just curious if it's something to look into? Thanks