"You are not required to use an oil from Ford's approved oil list, and Ford cannot deny warranty for using an oil that isn't on their approved oil list. The oil only needs to carry the correct Ford specification (WSS-M2C171-F1) and meet the correct viscosity requirements. AMSOIL will never be on a Ford approved oil list."
Well that's the dumbest response I've ever seen. So you are not required to use an oil from Ford's approved list, it just has to be an oil that carries their specification (which by default means it's on their approved list)? Um, ok....