ill only say this. I run the motorcraft 15w40 in my 96. reason?? we had a few,,in the ford garage where I worked for a bit,,that came in, running damn poor...come to find out,,they weren't running the mtrcrft..now before you howl,,this is designed for the smokes...and has more antifoaming properties in it..and that's what the owners of said vehicles had problems with..foaming in the oil,,and the injectors weren't firing.....changed them over to mtrcrft oil,,end of problem.............ymmv...................