Looking to replace all of the fluids in my 2002 Ford F150 and would like to get the best MPG possible. I do some towing with the truck, but basically a lot of back and forth to work and the cabin. I would like to go synthetic because I know they can usually offer better protection, better mpg, and longer service intervals but dont know much about this area of the vehicles lubrication system. Just for clafification i am looking to do front and rear difs, automatic trans, and transfer case. Thanks in advance for the help guys.