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.
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