1932 Rolls-Royce 20/25

Rolls-Royce launched the 20/25 in 1929 and remained in production for seven years during which time 3,827 examples were produced. During its production lifespan, numerous detail improvements were made with the most significant being an increase in compression ratio in 1930 and 1932. A synchromesh for the third and fourth gears was introduced during the latter years, along with an electric fuel gauge, a one-shot centralized lubrication system, and thermostatically controlled radiator grille shutters.

Within the Rolls-Royce family of automobiles, the 20/25 was a smaller and less expensive version of its stablemates, with simplified construction yet retaining the same uncompromised craftsman and quality. It catered to the increasingly important owner-driver market and was eminently suited to town use yet could perform admirably with Continental touring.

Rolls-Royce had abandoned its 'one model' policy in the post-World War I era, with an all-new 20hp car joining the existing 40/50hp Silver Ghost in 1922. It received unitary construction of the engine and gearbox, the latter featuring the modern innovation of a central ball change, together with a 'Hotchkiss drive' rear axle. The engine had overhead valves, a first for Rolls-Royce, with six cylinders and a displacement size of 3,127cc. It was initially paired with a three-speed transmission with central gear-change but replaced in 1925 by a four-speed gearbox with right-hand, gated change. That same year, four-wheel, servo-assisted brakes were also introduced.

The 20/25 hp, introduced in 1929, built upon the foundation of the 20HP, with an enlarged and more powerful engine. It was produced contemporaneously with the Phantom II and would become the best-selling Rolls-Royce of the inter-war period. Like other Rolls-Royce models of the era, all 20/25 HP vehicles wore custom coachwork. Most of the 3,827 examples produced were sold within the United Kingdom.

The six-cylinder engine had a displacement size of 3,699cc, a separate cast-iron block and aluminum crankcase, a seven-bearing crankshaft with a vibration damper, and pressure-fed lubrication. The bore measured 82mm and the stroke at 114mm. The carburetor was a single Rolls-Royce 2-jet type unit and the ignition system was independent coil and standby magneto. The suspension was comprised of semi-elliptic leaf springs and hydraulic dampers. Stopping power was provided by internal expanding four-wheel brakes, and mechanical servo motor driven from the gearbox.

by Daniel Vaughan | Jun 2021