I have a friend using it in his Ford Super Duty. He did my concrete work and we got talking and now he buys it through my P.C. membership. He seems to be happy with it. He likes that the truck seems to start better in cold weather. It seems to get good reviews on their site from customers. Biased source I know but FWIW.
Hey Steve - did he use it over last winter? Does he use a lot of makeup oil? NOACK seems high, but I'm used to seeing Amsoil with low NOACK usually, so this higher value for DZF may still be within 40w spec I suppose.