Pipeless416
07-31-2008, 06:06 PM
hello all, i was hoping to get some insight on using royal purple, or any synthetic lubricant in the transfer case and rear diff on a truck. a local 4x4 shop claims that they didn't believe the hype, but since trying the royal purple they have gotten a solid 3 mpg's better on everything it has been used in. could this possibly be true? we just got this 07 f150 lariat, and towing our quads we get 17 mpg highway which is pretty decent, especially compared to our old vans 11 mpg's.. but any little bit helps. thanks for any advice.