The stock market crash in late 1929 and resulting economic depression hit the automobile industry particularly hard; for the majority of Americans at that time a car was a luxury, not a necessity. General Motors faired much better than most automobile manufacturers; Pontiac sales were up over the numbers posted for 1930, as were dealer profits. The 1931 series 401 Fine Six wasn't a carry over model either, but a new body on a longer 112" wheelbase chassis.
The roadster and 4 door phaeton models were discontinued but a 2 door, 4 passenger cabriolet with roll-up windows was added to the model line. The remainder of the line consisted of a 2 door, 2 passenger coupe; a 2 door, 4 passenger rumble seat coupe; a 2 door 5 passenger sedan and a pair of 4 door 5 passenger sedans; a standard and a Custom.
The Fisher Body Vision-Ventilation windshield was still in use and the hood retained 31 thin vertical louvers per side but the latches were now controlled by a single, center- mounted handle. The v-shaped radiator featured chrome-plated wire mesh grille inserts for this year only. The wood-spoke wheels were modified from the previous year with semi-drop rims of enlarged area that effectively increased the air volume of the tire for a softer ride. These improved wheels were replaced by wire-spokes very early in the production run; the wire wheels utilized the same type of semi-drop rim to maintain the ride quality.
The 1931 bodies all offered increased glass area for a more open appearance that, combined with the wire wheels, offered an amazing change for the modern over the 1930 models. The longer frame was also improved with heavier gauge steel of more generous proportion, while the leaf springs featured rubber bushed eyes to cushion the ride. The mechanical brake system was also revised to improve the pedal feel and stopping ability.
The 200 CID six cylinder engines received full pressure lubrication to the front and rear camshaft bearings; improved engine mounts and the addition of a carburetor silencer built by AC. The rear axle was strengthened and improved by the addition of Hyatt roller bearings to support the drive pinion; the ratio was changed from 4.42 to 4.55:1.
While sales of the Pontiac models improved, the same wasn't true for parent company Oakland and this was to be the final production year for that marque. In January of 1932 it was announced that all models would now be known by the Pontiac name and in June the Oakland Motor Car Co. officially became the Pontiac Motor Company.