A deflector arrangement for a tractor is provided, the tractor being connectable to a trailer that forms an aerodynamic drag source. The deflector arrangement includes a deflector, a mount for connecting the deflector to the tractor, an arrangement for selectively deploying and retracting the deflector relative to the tractor, a sensor arranged to sense that the trailer that forms the aerodynamic drag force is attached to the tractor and send a loaded signal in response thereto, and a controller arranged to receive the loaded signal from the sensor and to control the selectively deploying and retracting arrangement to deploy the deflector in response to the loaded signal.