1921 Mercedes-Knight Tourenwagen

Text from the Mercedes-Museum:
"Beginning in 1911 Daimler-Motoren-Gesellschaft (DMG) equipped several car models with Knight engines. Invented by the American Charles Knight, the engines featured sleeve valves instead of conventional valves, and their exceptionally smooth operation was very convincing. The 16/45 hp Mercedes-Knight, of which more than 5,000 units were built, was the most successful Mercedes model until 1926."

Details:
Cylinders: 4
Displacement: 4084 cc (249 cu in)
Output: 45 PS (33 kW) at 1750 rpm
Vmax: 80 km/h (50 mph)