Approach towards Engine Downsizing with 48 Volt Diesel Hybrid SUV Meeting Future Emission Legislations in India

Emission legislation are becoming stricter day by day throughout the globe. India also has decided to shift from current BS 4 legislation to BS 6 legislation from April, 2020. Also the GOI is planning to implement CAFÉ legislation for meeting fleet CO2 targets of 113 g/km from the year 2022 onwards. All Indian passenger car manufacturers are currently focusing on meeting the stringent BS 6 legislations as well as the future CO2 legislation targets. For Diesel powered vehicles this change in legislation has made the industry to focus on newer technologies on the exhaust after-treatment system (EATS) side like DPF, SCR, LNT etc. On the engine side newer technologies like Variable Geometry Turbine (VGT) turbo chargers, closed loop EGR control, low pressure and high pressure EGR, higher fuel injection pressures and multiple injection capability etc. At the powertrain level hybridization would be another such technological shift which will be needed in future powertrains. Current 12 V micro hybrids which are present in Indian market has not much functionality with respect to major improvement in fuel consumption and emission. High voltage hybrid system has the highest potential compared to other hybrid layouts for reduction of CO2 and emissions with a significant pure electric driving range. This high voltage hybrid architecture has major impact on overall vehicle cost as well as require special safety related requirements which makes it not very suitable option to be immediately implemented considering the Indian market and available infrastructure. Sports Utility Vehicle (SUV) segment is dominated by Diesel engines greater than 2 L displacement in India and for this segment the next step towards meeting future BS 6 stage II (RDE cycle) and CAFÉ legislation would be 48 V hybrids.