The Armstrong-Whitworth was manufactured from 1904 (when the company took over construction of the Wilson-Pilcher) until 1919 (when the company merged with Siddeley-Deasy and began construction of the Armstrong Siddeley) in Coventry.
The Wilson-Pilcher was an advanced car, originally with a 2.4 litre engine, that had been made in London from 1901 until 1904 when production moved to Newcastle. Two models were made, a 2.7 litre flat four and a 4 litre flat six. The engines had the flywheel at the front of the engine. Drive was to the rear wheels via a preselector gearbox and helical bevel axle. The cars were listed at £735 for the four and £900 for the six. They were still theoretically available until 1907.
The first Armstrong-Whitworth car was the 28/36 of 1906 with a water cooled, four cylinder side valve engine of 4.5 litres which unusually had "oversquare" dimensions of 120 mm (4.7 in) bore and 100 mm (3.9 in) stroke. Drive was via a four speed gearbox and shaft to the rear wheels. A larger car was listed for 1908 with a choice of either 5 litre 30 or 7.6 litre 40 models sharing a 127 mm (5.0 in) bore but with strokes of 100 mm (3.9 in) and 152 mm (6.0 in) respectively. The 40 was listed at £798 in bare chassis form for supplying to coachbuilders. These large cars were joined in 1909 by the 4.3 litre 18/22 and in 1910 by the 3.7 litre 25 which seems to have shared the same chassis as the 30 and 40.
In 1911 a new small car appeared in the shape of the 2.4 litre 12/14, called the 15.9 in 1911, featuring a monobloc engine with pressure lubrication to the crankshaft bearings. This model had an 88-inch (2,200 mm) wheelbase compared with the 120 inches (3,000 mm) of the 40 range. This was joined by four larger cars ranging from the 2.7 litre 15/20 to the 3.7 litre 25.5.
The first six cylinder model, the 30/50 with 5.1 litre 90 mm (3.5 in) bore by 135 mm (5.3 in) stroke engine came in 1912 with the option of electric lighting. This grew to 5.7 litres in 1913.
At the outbreak of war, as well as the 30/50, the range consisted of the 3 litre 17/25 and the 3.8 litre 30/40.
The cars were usually if not always bodied by external coach builders and had a reputation for reliability and solid workmanship. The company maintained a London sales outlet at New Bond Street. When Armstrong Whitworth and Vickers merged, Armstrong Whitworth's automotive interests were purchased by J. D. Siddeley as Armstrong Siddeley.