Government of India has notified migration to Bharat Stage VI (BS VI) emissions norms for 2, 3 and 4 wheeled vehicles from 1st April 2020. For Agricultural Tractors, Construction Equipment Vehicles and Combine Harvesters (vehicles having power exceeding 37 kW) next stage emission norms Bharat Stage (CEV/TREM) – IV) are notified from 1st October 2020 and Bharat Stage (CEV/TREM) – V) from 1st April 2024. Test procedure for Type Approval and COP for above emission norms shall be as per various parts of AIS-137, as applicable. This Part 4 of AIS-137 prescribes Test Method, Testing Equipment and Related Procedures for Testing Type Approval and Conformity of Production (Cop) of Vehicles for BS-VI Emission Norms : Part-4 : BS VI Emission Norms for M and N Category Vehicles with GVW exceeding 3.5 tonnes.