The Rolls-Royce 20/25 was introduced in 1929 as the successor to the 20 hp.
The 20/25 retained the smaller-car concept of the 20 hp but used an enlarged six-cylinder engine, increasing displacement from 3,127 cc to 3,669 cc. The extra capacity improved performance, especially as coachbuilt bodies became heavier and more elaborate.
Rolls-Royce sold the car as a chassis, so customers generally selected an external coachbuilder for the body. This created considerable variation in appearance, although the mechanical identity remained the same.
The 20/25 was replaced by the 25/30 in 1936. It is sometimes mistaken for the Phantom II because both were introduced during the interwar period, but the 20/25 belonged to Rolls-Royce’s smaller-car line, while the Phantom occupied the larger and more prestigious position.