dndgib

My question is on the same lines but with regards to gear oil weight. I live in southern AZ and do some 1 1/2 hour highway driving during the summer where the temp gets to 115f ambient. I am concerned about trans and diff temps so I am thinking 85w140. It doesn't really get cold here so I am not overly concerned about the lower temp thickness. Does anyone have any recommendations for gear oils in this region of the hot ass SW?