OM 665 Superba History

Introduced at the 1923 Turin Motor Show, the 665 carried an all-new side-valve inline-six of 1,991 cc (bore/stroke 65 mm × 100 mm, approximately 55 bhp), offered on a shorter 2,800 mm wheelbase 'S' chassis or a longer 3,100 mm 'N' chassis. The name followed OM's convention: 6 cylinders, 65 mm bore. The public and press were so impressed that they dubbed it 'Superba' — a name OM eventually adopted officially.

The 665's finest hour came on 26–27 March 1927, when it won the first Mille Miglia outright. Ferdinando Minoia and Giuseppe Morandi took the victory in 21 hours 4 minutes 48 seconds at 77.24 km/h average; Tino Danieli and Renato Balestrero finished second, and Mario Danieli with Archimede Rosa third — a clean 1-2-3 sweep for OM. The car had also won the 1925 Tripoli Grand Prix and placed in the top five in the 2-litre class at Le Mans in 1925 and 1926.

From 1928 OM offered a supercharged SS variant, extending the competition life of the model and keeping it relevant through the early 1930s. The engine was also bored out to 2,184 cc in later production. Approximately 350 examples were imported to Britain by L.C. Rawlence and Co., many of which competed at Brooklands or received bespoke touring coachwork. The MM suffix was applied to later cars in honour of the Mille Miglia win. Production ended circa 1932, two years before Fiat's acquisition closed OM's automobile chapter.