Which engine is there in TVS Zeppelin BS4 or BS6?

TVS Zeppelin is powered by an air-cooled single-cylinder 224 cc engine with oil-cooler technology. It is available in both BS4 and BS6 versions. The BS4 version has a maximum power output of 20.4 BHP and a peak torque of 18.4 Nm, while the BS6 version has a maximum power output of 20.2 BHP and a peak torque of 18.3 Nm. The engine is mated to a 5-speed gearbox.