The Lanz Bulldog D8539 is a high-speed road model tractor produced by Lanz from 1935 to 1955 as part of the D85 Series. It features a 10.3L single-cylinder liquid-cooled diesel engine producing 34.3 hp (25.6 kW) at 540 RPM. The tractor has a 6-speed gear transmission and 2WD drive. It was built in Mannheim, Baden-Württemberg, Germany, and is known for its solid cab design.