I have a 2016 Ford Explorer Limited with the 3.5 NA v6. I need to change my PTU fluid. It calls for 75w140 but due to the huge heat load and small filling capacity of this unit I was wondering if you guy would advise using something different. Maybe a synthetic 80w140 or even Redline Lightweight Shock proof? The unit is known to hit 250-290F temps. I plan to change the fluid every 25k miles.