As emission regulations tighten and resource scarcity looms, the automotive industry faces an imperative to innovate. “CAFE norms are becoming stricter by the year. As the emission norms become stricter, auto OEMs have to go beyond the customary techniques of doing the after-treatment, and lightweighting is the obvious choice. There’s no other way to do it,” Mahindra & Mahindra’s (M&M) SVP Ritesh Agarwal said at Autocar Professional Vehicle Lightweighting Conference.
Talking about how lightweighting has become essential to meet these challenges and drive sustainable mobility, he says that lightweighting is crucial not only for meeting regulatory requirements but also for improving vehicle performance. “A 10% reduction in weight can boost fuel efficiency by 6-8% in internal combustion engine (ICE) vehicles and increase the single-charge mileage of electric vehicles (EVs) by 13%. EVs have an added baggage of battery and high voltage systems which increases the weight by 350 kgs,” Ritesh Agarwal, Head – Sourcing, Auto Sector, M&M explains. “This weight actually reduces the single charge mileage that you get on the vehicle. You have to counter that by lightweighting.”
Lightweighting also plays a critical role in sustainable mobility by addressing resource scarcity. “For sustainable mobility, the first thing is the scarcity of the resource itself. How do you counter that? By consuming less, and for that, you need to do lightweighting,” says Agarwal.
M&M has proactively reduced vehicle weight by at least 200 kgs to meet current CAFE norms. The company employs a mix of materials, including aluminium and high tensile steel, to achieve this. However, there are cost challenges associated with lightweighting.
“The cost challenge comes from the migration of lightweighting,” Agarwal points out. “But there’s a level to which you can stay at the current cost with lightweighting. Beyond that, when it’s guided by stringent regulatory norms, then you have to bear the cost. So, you have to very intelligently manage the cost.”
The evolution of the steel industry highlights the advancements made to support lightweighting. “In the 1960s, there were only 5 grades of steel, but today we have more than 175,” Agarwal states. This evolution allows for balanced structural strength tailored to various vehicle needs. However, challenges remain, particularly with advanced materials like ultra-high strength steel, which is not produced in India due to lack of economies of scale. “Localisation becomes a limitation,” Agarwal says. “That’s where the nearest is aluminium, which is also mostly imported.”
Recycling poses additional challenges. While recycling aluminium is feasible to an extent, recycling magnesium, a highly flammable material, is problematic due to the lack of facilities, he adds.
Reliance on imported materials for lightweighting introduces significant risks. “Since most of the material that goes into advanced lightweighting and the supply chain is dependent on countries outside India, there’s a huge risk to it,” Agarwal explains. Uncertain volumes often result in either excess or shortage of materials, leading to inventory costs and obsolescence risks.
To address these challenges, M&M employs technologies like hot stamping, which offers structural strength at a lower cost, and honeycomb materials for weight and cost reduction. Additionally, advancements in engine technologies, such as integrating an engine oil cooler, help reduce costs by consolidating parts.
“Hot stamping is one technology we’ve used extensively to achieve lightweighting,” Agarwal says. “Honeycomb material is another way to achieve cost reduction. As engine technologies progress, integrating an engine oil cooler allows for cost reduction through part integration.”
As the automotive industry grapples with stricter emission norms and resource scarcity, lightweighting emerges as a critical strategy. Through innovative material use and advanced technologies, companies like Mahindra & Mahindra are leading the way in achieving sustainable mobility and meeting regulatory challenges.