OM, an abbreviation for Officine Meccaniche, was established in 1899 in Milan, Italy, with its initial focus on the production of railway stock. The formation of the company resulted from the merger of Grondona Comi & C and Miani Silvestri & C. By the year 1918, OM transitioned its manufacturing efforts to automobiles following the acquisition of the Zust Car Company located in Brescia, Northern Italy.
The inaugural automobile produced by OM was the Tipo S305, which drew significant inspiration from the earlier Zust models. This vehicle marked the first instance of the OM badge and remained in production until 1923. It featured a four-cylinder side-valve engine with a displacement of 4712cc, generating 30 horsepower. In 1919, OM introduced a new model that was distinct from the previous Zust designs, named the 465. This model was equipped with a 1327cc four-cylinder engine. The designation '465' was derived from the engine's configuration, specifically the '4' representing the number of cylinders and the stroke measuring 65mm. The vehicle was fitted with a three-speed manual transmission that directed power to the rear wheels. It was available in multiple body styles, built on either a 2700mm short wheelbase or a longer 2900mm wheelbase, with the torpedo configuration accommodating four passengers being the most favored option.
In 1921, OM launched the Tipo 467, which remained in production until 1923. This model was succeeded by the Tipo 469 in 1922. The Tipo 467 featured a four-cylinder engine with a stroke of 67mm. In contrast, the Tipo 469 boasted a 69mm stroke and holds the distinction of being the longest-produced model in OM's history, continuing until 1934. The engine of the Tipo 469 had a displacement of 1496cc and generated 30 horsepower. It was offered exclusively with a wheelbase of 2800mm.
Among OM's most renowned models was the Tipo 665, commonly referred to as the Superba. This model was manufactured from 1923 to 1932 and was available in two variants: the 665N and the 665S. The 'N' variant was built on a 3100mm wheelbase, while the 'S' variant utilized the standard 2800mm wheelbase. Both variants shared the same mechanical specifications, featuring a six-cylinder side-valve engine with a displacement of 1991cc, initially producing 40 horsepower. Over the years, both the engine and the vehicle underwent significant advancements.
The early 1930s marked the introduction of a new 2200cc engine, which elevated the horsepower to 55. This engine was utilized in the 665 N5 and the 665 SMM models. The N5 was designed on a wheelbase of 2790mm and featured a narrower track, although the track width was expanded in 1930. The 665 SMM commenced production in 1928, succeeding the 665S, and boasted enhancements including a wheelbase of 2790mm.
The horsepower was further augmented when OM incorporated a supercharger into their 2200cc engine, leading to the creation of the 665 SS MM Superba Compressore, which was produced in limited quantities from 1930 to 1931.
In 1933, OM merged with Fiat, subsequently redirecting its focus towards the manufacturing of commercial vehicles.
by Dan Vaughan