BMW 3/15 DA range
|1929 to 1932|
Bayerische Motoren Werke AG (BMW)
|Production||1929-1931: BMW DA-2
1931-1932: BMW DA-4
1930-1931: BMW Wartburg DA-3
|Body and chassis|
|Engine||747 cc side valve straight-4, 15 hp (11 kW)
(DA-2 & DA-4)
18 hp (13 kW)
|Wheelbase||1,905 mm (75 in)|
|Length||3,000 mm (120 in) (DA-2 & DA-4)|
|Width||1,275 mm (50.2 in) (DA-2 & DA-4)|
|Height||1,625 mm (64.0 in) (DA-2 & DA-4)|
|Kerb weight||approx. 400 kg (882 lb) (laden weight)|
The 3/15 DA-2 replaced the DA-1 in April 1929. The main change from the DA-1 was the operation of the foot brakes, controlled via cable linkage, now acting on all four wheels: brakes on the DA-1 had operated only the rear wheels. Other changes included larger tyres and a lower final drive ratio. There was no change in either the size or the claimed output and performance from the car's four cylinder four-stroke side-valve engine.
Available body styles included a steel-bodied two-door saloon, a two-seat convertible, and a delivery van.
3/15 DA-3 Wartburg
The 3/15 DA-3 Wartburg was a sports roadster version of the 3/15, and was consequently BMW's first sports car. A drop-centre front axle was used to lower the frame for a lower centre of gravity. The compression ratio of the engine was raised from 5.6:1 to 7.0:1, raising maximum output to 18 bhp (13 kW; 18 PS) at 3500 rpm.
Despite sharing the wheelbase and track of the other models, the Wartburg bodied roadster was 100 mm (3.9 in) longer, 125 mm (4.9 in) narrower and at a height of just 1,300 mm (51 in), 325 mm (12.8 in) lower than the standard bodied DA-2 and DA-4 cars.
The Wartburg was introduced in 1930, and the Great Depression had drastically reduced the market for sports cars It was discontinued in 1931, with 150 sold.
The 3/15 DA-4 replaced the DA-2 in mid-February 1931.
While the engine, gearing, and chassis of the DA-4 were unchanged from the original Dixi 3/15 PS DA-1, the DA-4 was a step away from the original Austin design. The DA-4 was the first BMW automobile with independent front suspension, which used the ends of the transverse leaf spring to act as lower control arms, with further wheel location performed by two diagonal leading arms.
The DA-4 was heavier than the DA-2, and a larger wheel diameter was used to compensate for this.
The Austin-based 3/15 series was discontinued before the March 1932 expiration of BMW's licence to manufacture Austin Sevens. It was replaced by the BMW 3/20.