India, Feb. 11 -- India is set to change how BS6 emission testing works from April 1, 2027, and it will affect every new car that goes through certification. The government will move to the Worldwide Harmonised Light Vehicle Test Procedure, or WLTP, replacing the Modified Indian Driving Cycle used so far. The new test cycle will apply to passenger cars and light commercial passenger vehicles under five tonnes. For anyone who keeps an eye on official mileage figures and spec sheets, this shift matters because the numbers printed for fuel efficiency and emissions will come from a different test method. Carmakers will need to retune engines, update software and run fresh certification tests, so the move will shape future launches, facelifts ...