Originally Posted by
Graham11
Raising the spur tooth count does not have the same effect as raising a front or rear diff ring gear tooth count. Under driving the rear makes it feel like the front of the car is pulling the car around in my opinion. A 48t simply raises top speed and removes some low end
It isn't the same if you only use the underdrive in one diff, but some guys were talking about using it in the front and the rear at the same time.