“Increase in weight of the car does reduces energy efficiency and increases CO2 emission, if all other factors remain the same,” said Rahul Bharti, executive director – corporate affairs, Maruti Suzuki, the country’s largest carmaker. Also, the addition of more safety and convenience features into the car “implies fitment of more equipment in the car and that does increase the weight of the car”, he said.
So, to have more features and still have lower CO2 emissions, carmakers employ high strength-to-weight ratio materials like high tensile and ultra-high tensile steels, aluminium alloys, carbon fibre and other engineering performance materials.
“We are also using the Suzuki Tect and Heartect platforms, which achieve a high structural rigidity with lower weight,” Bharti said.
For most car companies, the journey of lightweighting is ongoing with the improvement of technologies, Indian manufacturing capabilities and more local sources.
“The usage of high-strength steels and hot-stamped parts have also increased in our new age cars,” said Mohan Savarkar, chief product officer at Tata Motors Passenger Vehicles. “On our older vehicles like the Tiago, we have been able to reduce around 30 kg through various measures.”
R Veluswamy, president – automotive division, Mahindra & Mahindra, said the new generation cars have increased in length and width. With the introduction of the crash norms, the transition to BS6 and the addition of convenience features such as panoramic sunroof, dual display screens, ADAS systems, ventilated seats, etc, which have increased the weight of a car by at least 160 kg.
“However, through various weight reduction measures, we have managed to reduce the weight of our SUVs,” he said. “The XUV-700 vehicle weight was reduced by 79 kg compared to the XUV-500 in spite of several new feature additions, vehicle length increase, and meeting GNCAP 5-star crash ratings.”
Also, the new platforms, improvement in powertrain, and use of plastics help in keeping vehicle weight under control and improve fuel efficiency, said Ravi Bhatia, president at Jato Dynamics.
While the overall fleet gets heavier, passenger vehicles are also getting cleaner as increasing sales of plug-in hybrids, electric vehicles, CNG and ethanol options is changing the fuel mix, offsetting the emissions from larger vehicles.
While the weighted average kerb weight of passenger vehicles sold in the country increased 3% in two year to 1,394 kilograms in calendar 2023, the average CO2 emission reduced from 148 g/km in 2021 to 129 g/km in 2023, data collated by Jato Dynamics show.
EV sales grew 95% on year to 95,473 units in 2023 while hybrids, which include HEVs and PHEVs, grew 407% to 88,651 units, according to Jato Dynamics data.