A braking system for the control of vehicle speed, the vehicle including an engine having a first plurality of engine cylinders, an electronic throttle, electrical power source and engine brake adapted to provide engine braking, comprising an electronic control unit in communication with the engine electrical power source, engine throttle and engine brake, and a speed sensor adapted to measure the speed of the vehicle and communicate the measured vehicle speed to the electronic control unit, wherein when the measured vehicle speed is greater than a pre-determined vehicle speed threshold, the electronic control unit disables the engine throttle and applies the engine brake using a second plurality of the engine cylinders, the second plurality of engine cylinders being less than the first plurality of engine cylinders.