The 20hp was Rover's first multi-cylinder engined car. Specially lightened versions were entered for the first Tourist Trophy race held in the Isle of Man in 1905. In 1907 Rover won the event with a car driven by Ernest Courtis who was Rover's chief tester at the time. His average speed was 28.8 mph over six laps of the 40.3 mile circuit.

The 20hp remained in production until 1910. It featured an engine brake and was the first production model to carry the shield shaped radiator, a characteristic Rover identification mark.

This example was re-registered by the Rover Company in the 1960s with the registration mark 'ROV 4' because the 20hp was the company's first four cylinder model.