The following result is obtained by our Internet Research Algorithm: BS6 means cleaner exhaustion, less particulate matter & less toxic gases. In the BS6 diesel engine, hydrocarbon (HC) reduces to 43%, particulate matter (PM) + nitrogen oxide (NOx) reduction of 68% and NOx reduction of 82%. This means BS6 diesel engine is 80% cleaner exhaustion. Changes in the engine - The main changes are in after treatment, When exhaust comes out of the Turbo Charger it passes through DOC (Diesel oxidation Catalyst) then DPF ( Diesel Particulate Filter) then SCR ( Selective Catalytic Reducer) and then ASC (Ammonia Slip Catalyst) which is an option to be fitted. The engine also consists of an air control system such as turbo speed controller intake air throttle control valve or exhaust throttle control valve.