Looking up the specs for the rear end in my wife's 2012 Mustang V6, it says it takes 75w-140. Why? I could understand it in a 9" rear in a truck that'll see heavy duty use, but an 8.8" with 2.73 gear behind a V6 pony car? Any reason a high end 75w-110, such as HPL Diff Life 75w-110, wouldn't work in that rear end? I know there was some controversy over this, but haven't really dug into why.