A neatly restyled version of the 600, Fiat introduced its 850 sedan in 1963. The car had the same basic layout as the 600, with two doors, 2+2 seating, and a four-cylinder, water-cooled, longitudinal rear-mounted engine with transaxle. The 850 was a huge seller in its basic two-door sedan form, with 1,780,000 produced. There was also a handsome fastback coupe produced from 1965 to 1972, which found 342,873 buyers. The best known model in the U.S. is the Bertone-styled 1967-73 850 Spider, of which 124,600 were sold. A surprising number of these Spiders still exist, though sourcing one of their auxiliary hard tops is difficult.

Engine displacements ranged from 817 cc, (sizes below 60 cid were not subjected to 1968 emissions regulations) to 843 cc in the sedan and rarely-seen Familiale Volkswagen-style Transporter, and 903 cc in the Spider and coupe, which were capable of nearly 90 mph. Horsepower ranged from 34 hp to 52. The 850 boasted independent suspension by transverse leaf at front and coils and trailing links at the rear, and the Spider had front disc brakes.

All 850 models are quite lively and gas mileage averages around 35 mpg. Production was sufficiently large that mechanical spares present few serious problems, but Fiat’s casual dealer network and the company’s absence from the U.S. from about 1980 to 2011 has meant that NOS parts can be expensive. In general, the only real problem with any Fiat 850 is rust, but it is a profound problem and demands detailed examination of any potential purchase, preferably on a lift.