In 1957, NATO had specified that its forces should use multi-fuel engines. The early BL Engine delivered around to the sprocket, which meant a top road speed of around and cross-country performance was limited. This was further hampered by the Horstmann coil spring suspension, which made it a challenge to drive cross country and provide the crew with a comfortable ride. Due to the cylinder linings being pressure fitted, coolant leaks within the cylinder block were common, resulting in white smoke billowing from the exhaust.