In line with global peers (EU, Japan, etc.), the Automotive Industry Standard (AIS) Committee in India has decided to adopt “World harmonized Light vehicle Test Procedure (WLTP)” for M2 and N1 category vehicles not exceeding 3500 kg and for all M1 category vehicles. As a result, “World harmonized Light-duty vehicles Test Cycle (WLTC)” is set to replace currently applicable “Modified Indian Drive Cycle (MIDC)” in the next couple of years. The draft Corporate Average Fuel Economy (CAFE) III & CAFE IV norms for CO2 emission limits, which are set to be implemented in year 2027 and 2032 respectively refer to a shift to WLTP from MIDC. The latest draft of Central Motor Vehicle Rules (CMVR) for BS-VI emissions is also being revised to use WLTC as test cycle. This migration to WLTC is in sync with the demand for test procedures to replicate real driving conditions more appropriately. Further, the move to WLTC along with stricter emission norms is a major step towards realizing India’s COP26 pledge to achieve net zero emissions by 2070.
WLTC being much more dynamic with higher average speeds and acceleration compared to MIDC, has a major impact on the vehicle CO2 emission. Other gaseous pollutants like NOx also increase significantly with WLTC. This study takes into consideration the impact of change in test procedure on a conventional small commercial vehicle. Using the well validated models from FEV, simulations are performed to quantify the differences in various gaseous emissions under both MIDC and WLTC as well as under a typical Indian Real Driving Emissions (RDE) cycle with base calibration. Further, a step wise approach is detailed to have vehicles compliant with upcoming norms. The methodology lists both basic measures like calibration and hardware upgrades (e.g., change in injection pressure) as well as advanced measures including deploying additional technologies like advanced aftertreatment systems and hybridization etc. to improve fuel efficiency as well as reduce tail pipe emissions.