[RC-Monster Mike]

Ideal diff oil selection will vary greatly with track conditions. On a loose or rough track, thinner oil is typically better (I like 5K in the front and center and 1K in the rear). A high traction, smooth running surface will call for thicker oil (on smotth surfaces, I would probably run 20K in the center, 10K in the front and 5K in the rear). Rough tracks require more diff action, so lighter oil is in order. A smooth track requires maximum traction(less wory about spinning out), so heavy oil is in order.