Ether Rotary Engine
Since the discovery of raw Ether, vehicles have become commonplace. Road vehicles operate by injecting Illuminated Ether into the wheels in the direction of travel, and decelerate by direct ejection of illuminated ether from the chassis front, or whichever direction a push is required. Because of this, a vehicle accelerating will have brightly glowing blue wheels, and braking will cause the bumper (in the case of a car) to glow. Constant speeds will only cause a slight blue glow in the wheels.