The Duesenberg Model J of the 1920s featured a dual-ignition system with two spark plugs per cylinder and two independent magnetos, a redundancy that was engineered not for safety but because Duesenberg’s engineers discovered that the extreme combustion pressures of their high-compression engines could occasionally foul spark plugs so rapidly that a single ignition system would fail mid-drive, forcing them to engineer reliability through deliberate duplication rather than solve the underlying fouling problem.
Car Fact #71 — August 26, 2026
