1931 Buick Series 90

During the first three decades of the 20th century, Buick's popularly priced automobiles were equipped with overhead-valve engines. By the early 1930s, Buick engineers felt the long-lived six-cylinder engine had reached its limits in size and efficiency. In 1931, Buick introduced an all-new straight eight-cylinder engine used to power an entire line of models, with the top-of-the-line being the Series 90. Its eight-cylinder engine offered just over 100 horsepower and incorporated such innovations as an oil temperature regulator to cool the engine at high speeds and warm it in cold weather, as well as thermostatically controlled radiator shutters, as found on Packards and Duesenbergs. Many of the Fisher bodies fitted to the Series 90 Buick were shared with Cadillac.

The all-eight cylinder Buick lineup ranged from 221- to 345- cubic-inches and only a few parts were interchanged among the three engines. Buick offered four different series of cars which included the 50, 60, 80, and 90. The Series 90 was available in eight different body styles and had a wheelbase of 132 inches. The convertible coupe was introduced partway through the year and had a leather interior in a similar fashion to the other open body styles. The closed body styles had mohair interiors with silk roller shades for the rear side and rear window.

The entry-level model for Buick in 1931 was the eight-cylinder Series 50 priced from $1,035 to $1,095. The sedan and convertible body style were both the most expensive of the range, with a price of $1,905. The sedan was also the most popular of the entire list of 1931 Buicks, with 33,184 of the Series 50, 30,665 of the Series 60, and 14,731 of the Series 80. The Series 50 rested on a 114-inch wheelbase platform, the Series 60 measured 118-inches, and the Series 80 at 124-inches. The 220.7 CID OHV inline-8 powering the Series 50 produced 77 horsepower while the Series 60's inline-8 displaced 272.6 CID and produced 90 horsepower. The Series 80 shared its 344.8 CID inline-8 with the Series 90. All 1931 Buick engines were backed by a sliding gear, three-speed synchromesh transmission, rode on wooden spoke wheels on demountable rims, and had mechanical brakes on all wheels. The Series 60 was priced from $1,285 to $1,355, and the Series 80 was priced at $1,535 for the coupe and $1,565 for the Sedan.

All 1931 Buicks wore a radiator cap bearing a figure 8, had a revamped instrument panel, a new cooling system, and lower front seats with deeper seat cushions. The interior of the Series 50 was either mohair or cloth upholstery, the Series 60 had either mohair plush or cloth of higher quality than that of the Series 50, and the Series 90 used mohair plush interior on closed body styles.

Three of the eight body styles of the Series 90 had seating for seven passengers, including the sedan priced at $1,935, the limousine at $2,035, and the phaeton priced at $1,620. 4,159 examples were built of the sedan, 514 of the limousine, and 392 of the Phaeton. The five-passenger sport sedan priced at $1,785 was the most popular Series 90 body style with 7,853 units built, followed closely by the five-passenger coupe with 7,705 built with a base price of $1,765. The Country Club Coupe with seating for four was fairly popular with 2,990 examples built, priced at $1720. The two-door sport roadster with seating for four was priced at $1,610 and 824 units were built and 1,066 examples of the four-passenger convertible coupe were built with a base price of $1,785.

For 1931, roughly 25,503 examples of the Series 90 were built which accounted for about 18 percent of total Buick production. The 1931 Series 90 represented the beginning of a Cadillac-Buick rivalry for high-end luxury sales that would continue throughout the remainder of the 1930s.

by Daniel Vaughan | May 2019