OM, meaning Officine Meccaniche, was founded in 1899, in Milan Italy and produced railway stock. The company was the result of a merger between Grondona Comi & C and Miani Silvestri & C. By 1918, the company switched production to automobiles after taking over the Zust Car Company of Brescia, Northern Italy.
OM's first car was the Tipo S305 which borrowed heavily from the prior Zust vehicles. It was the first vehicle to wear the OM badge and remained in production until 1923. It was powered by a four-cylinder side-valve engine that displaced 4712cc and produced 30 horsepower. In 1919, a new model was introduced, which was not based on prior Zust vehicles. It was dubbed the 465 and powered by a 1327cc four-cylinder engine. The name '465' was chosen to represent the engine configuration, mainly the '4' cylinders and the stroke of 65mm. There was a three-speed manual gearbox which sent the power to the rear wheels. This vehicle was offered in a variety of body-styles in a 2700mm short wheelbase or on a longer, 2900mm wheelbase. The torpedo configuration with seating for four was the most popular setup.
In 1921, OM introduced the Tipo 467 which stayed in production until 1923. It was followed by the Tipo 469 in 1922. The 467 had four-cylinders and a 67mm stroke. The 469 had a 69mm stroke and would remain in production the longest of all the OM models, lasting until 1934. The engine in the 469 displaced 1496cc's and produced 30 horsepower. The only wheelbase offered was 2800mm.
The most famous and memorable model from OM was the Tipo 665, also known as the Superba. It was in production from 1923 through 1932 and was available in two versions, the 665N and the 665S. The 'N' version sat atop a 3100mm wheelbase while the 'S' remained on the traditional 2800mm unit. Both versions had the same mechanical configuration, being powered by a six-cylinder 1991cc side-valve engine capable of producing 40 horsepower initially. As the years progressed, so did the engine and the vehicle.
The beginning of the 1930s saw a new 2200cc engine that increased horsepower to 55. This was used in the 665 N5 and the 665 SMM. The N5 was built atop a wheelbase that measured 2790 and had a narrower track, though it increased in 1930. The 665 SMM had entered production in 1928 and replaced the 665S. Improvements included a wheelbase of 2790mm.
Horsepower increased when OM attached a supercharger to their 2200cc engine. The result was the 665 SS MM Superba Compressore which was constructed in small numbers between 1930 and 1931.
In 1933, the OM company was merged with Fiat and soon, OM's efforts would be turned toward the production of commercial vehicles.By Daniel Vaughan | Apr 2007