Differential = class("Differential") function Differential:initialize(options) options = options or {} self.power = options.Power or 1 self.coast = options.Coast or 1 self.preload = options.Preload or 10 self.viscousCoeff = options.ViscousCoeff or 0.9 self._gearbox = options.Gearbox self._leftWheel = options.LeftWheel self._rightWheel = options.RightWheel if self._gearbox then self._gearbox:linkDiff(self) end end