I have a 2018 GT with a Torsen differential, Ford recommends a weight of 75w-90 and I read on the Torsen web site that they recommend 75w-140 for their differential. In addition Ford adds a slip lock additave to their differential gear lube but the Amsoil Severe Gear that I will be using has some of this addative in it already. The Torsen site gave some reasons whey they recommend 75w-140 so I'm going to go that way. Has anyone used the 75w-140 in their Torsen and if so did you have any...

Torsen differential gear lube weight