Delage DI / DIS / DISS History

Introduced in 1923, the DI (and its sports siblings DIS and DISS) became the volume backbone of Delage's road-car business. The engine was a 2,121 cc four-cylinder with overhead valves, a bore and stroke of 75 × 120 mm, and a four-speed gearbox; four-wheel brakes were included — advanced for the era.

Priced at £475 in England, the DI undercut many rivals while delivering genuine pace: sports versions fitted with aluminium pistons were considered quite fast by 1920s standards. Combined production of the DI, DIS and DISS reached 10,709 examples between 1923 and 1927, making it the most commercially successful Delage of the independent era.

The DI's sales success subsidised Delage's expensive Grand Prix programme of the mid-1920s, which culminated in the 1927 World Championship — an uncomfortable financial dependency that contributed to the company's eventual overextension.