The M 25 supercharged eight-cylinder in-line engine was fitted in the Mercedes-Benz W 25 racing car, the first Silver Arrow. The M 25 E was the last variant of the power-plant and saw race action in the 1936 season. Its displacement was boosted to 289 cubic inches and its output could reach 473 hp (348 kW) depending on the supercharger, the fuel used and the set point.