[Sneeck]

Most people use 7k front 5k rear for the first time, infact it's recommanded in the manual. Why I don't know but it work's.

With a brushless motor and thin oil it's hard to notice a difference, there is so much torque that thin oil ain't gonna do much. Unless you really want to hill climb i'd put 10k front and rear, but I have no idea how this would affect the truck's handeling. One thing to keep in mind, the heavier the oil, the larger your turning circle would be.