Depends on your motor, ESC, battery, and where you mount everything. I put my truck on the scales last night, and the balance was close enough to even, that I don't have to add any weight. I'm running an RX8, mounted back almost against the motor, no radio box or radio tray, with the receiver right infront of the RX8. Running a Tekin SC4X 4.5 motor, and a Gens Ace 5000 lipo shifted all the way back. A smaller, lighter ESC and/or motor, or a heavier lipo may require adding ballast weight to balance the truck side to side.