[RC-Monster Mike]

It depends on the weight of the truck. My Lipo Maxx weighs barley 8 pounds (slightly under) in full race trim (RTR). I have run 4s on my xl2400 and find it to be quite nice in terms of power. The 5s turns the power up to the insane level, while 6s is downright retarded! The 9L is pretty similar performance wise to the xl2800. 4s 3200 Lipo packs will run lightly longer than nimhs packs (slight advantage because they have a lot less weight to drag around). The 5s, when used with a slow motor (xl2000, for example) can deliver the same power for 25% longer in theory.