 Additionally, the engines were widely used in industrial, light aircraft and kit car applications.Like the Volkswagen Beetle produced after the war, the first Volkswagen Transporters (bus) used the Volkswagen air-cooled engine, a 1.1 litre, DIN-rated 18 kW (24 PS, 24 bhp), air-cooled four-cylinder "boxer" engine mounted in the rear.The 22-kilowatt (29 PS; 29 bhp) version became standard in 1955, while an unusual early version of the engine which developed 25 kilowatts (34 PS; 34 bhp) debuted exclusively on the Volkswagen Type 2 (T1) in 1959.