With a lower viscosity fluid, 10000 or 30000, the diff will have more action allowing the wheels to adjust to the different speeds easier. This will create more traction for that end of the car. For a low bite track, you may want to run a diff in the front with a heavier fluid or even a spool with some 7,000 ot 10,000 in the rear. When I ran it like this, I used 30,000 in the front and 10,000 in the rear. I hope this helps.