Magnesium's Strategic Shift in EV Lightweighting: India's Early Opportunity
This analysis is authored by Srihari Mulgund, Partner and New-Age Mobility Leader at EY-Parthenon, and Mayur Kalgutkar, AVP at EY-Parthenon. Magnesium is poised to move from a "nice to have" to a strategic imperative in automotive lightweighting, and India has a unique opportunity to act early and decisively.
The Evolution of Lightweighting in the EV Era
For decades, automotive lightweighting was treated as a supporting act—useful for improving fuel efficiency but rarely decisive. That paradigm has changed irrevocably in the electric vehicle (EV) era. Every additional kilogram in an EV compounds battery size, increases thermal load, necessitates structural reinforcement, and ultimately raises total cost. Consequently, lightweighting is no longer merely a materials-engineering exercise; it has become a critical system-level strategic lever.
While aluminum has long been the material of choice for lighter structures, magnesium—the lightest structural metal available—is shifting from a niche curiosity to a strategic priority. As original equipment manufacturers (OEMs) relentlessly chase every incremental efficiency and cost advantage in their EV platforms, magnesium is rapidly moving to the center of the conversation.
Global OEMs Accelerate Magnesium Adoption
Nations with abundant domestic magnesium reserves recognized this shift early and moved decisively. They have increased magnesium content per vehicle, particularly in premium New Energy Vehicles (NEVs). These leading nations are estimated to have boosted magnesium usage to approximately 15–20 kilograms per vehicle by expanding the application of magnesium die castings into large structural components.
- Instrument panel beams
- Seat frames
- Transmission housings
- Body gigacastings
Some are even supporting a broader industrial push aimed at reaching ambitious targets of 45 kilograms of magnesium per vehicle by 2030. Western OEMs are also actively evaluating magnesium's role in lightweight structures. This is evident in Tesla's use of magnesium within body systems and in European brands like BMW and Audi integrating it into gearboxes, frontend structures, and seat frames. Tightening EV economics and competitive benchmarks will continue to compel Western OEMs to accelerate magnesium integration.
Why Magnesium Castings Are Gaining Ground Now
Magnesium's core advantage lies in its weight: it is about 30–35% lighter than aluminum and significantly lighter than steel. This is further enhanced by properties particularly valuable in EVs:
- High specific strength
- Good heat dissipation
- Intrinsic electromagnetic shielding
- Excellent vibration damping, enabling quieter cabins
Magnesium also melts at moderately lower temperatures than aluminum, aiding energy-efficient casting. Beyond material traits, process advances in semi-solid techniques like thixomolding are changing the game. These enable thinner wall sections, lower processing temperatures that reduce casting defects, and improved surface finish and mechanical consistency. Meanwhile, new magnesium alloys and surface treatments have addressed historical concerns regarding corrosion and casting quality, broadening structural applications.
India's Moment of Choice: Start with Cast Magnesium Alloy Wheels
For India, the magnesium opportunity is fundamentally about timing. The EV and lightweighting journey is still in its early stages, with architectures and material choices remaining fluid. The risk of waiting too long could lock OEMs into aluminum-heavy platforms just as global benchmarks pivot toward deeper lightweighting.
The shortest—and smartest—path for Indian OEMs is cast magnesium alloy wheels. Aluminum alloy wheels have already reached approximately 38–40% penetration in passenger vehicles, creating a familiar upgrade path for both OEMs and consumers. Magnesium wheels build directly on this momentum, offering the next logical step rather than a disruptive leap.
A simple 16-inch wheel case illustrates the compelling economics. A cast magnesium wheel delivers roughly 30% weight reduction. In recent years, magnesium prices have often traded at 1.2–1.5 times aluminum prices and have steadily fallen as Chinese supply scaled and processes improved. In FY25, the magnesium-to-aluminum ratio even dropped below 0.8 times in China. Using a conservative 1.4 times magnesium-to-aluminum price ratio, the price of the 30% lighter magnesium wheel roughly balances against aluminum.
Furthermore, the weight saving translates into meaningful downstream battery-pack savings of approximately US$24 at US$80/kWh. Thixomolding equipment capital expenditure is US$3.0–3.5 million for a 3,000–3,500-ton press. Even with a 5-year economic life, the combined effect yields a net benefit of US$4–18 per vehicle, depending on annual production and battery-pack cost assumptions. Higher volumes and higher battery-pack costs quickly tilt the economics in magnesium's favor, making wheels a low-risk, analytically sound entry point for Indian OEMs.
Electric Motorcycles: The Strategic Wildcard
If passenger cars represent the obvious opportunity, electric motorcycles may be the more strategic one. India's two-wheeler market is electrifying rapidly, led by the scooter segment. However, motorcycle electrification continues to struggle because battery weight significantly compromises range, handling, and rider appeal. This is precisely where magnesium can fundamentally change the design narrative.
Components such as swing-arms, motor housings, wheels and wheel hubs, frames, and even battery enclosures are prime candidates for magnesium substitution. Weight savings here translate directly into either longer range or smaller, cheaper batteries—effectively redefining the motorcycle design equation. Unlike cars, where aluminum is deeply entrenched, two-wheelers offer a cleaner slate. OEMs can design magnesium in from the outset, potentially leapfrogging global peers.
Addressing the Supply Chain Dilemma
One potential reason holding back Indian OEMs could be supply risk, often creating exposure to policy, pricing, and logistics shocks. This can be mitigated by progressively reducing import dependence through emerging EU and Rest of World (ROW) projects as volumes scale. Additionally, domestic recycling and remelting loops for magnesium components can be established. These steps could transform a single-point risk into a manageable, diversified supply strategy.
Conclusion: A Window That Won't Stay Open
Magnesium's moment has arrived not because it is new, but because industry constraints have fundamentally changed. Major economies are moving in that direction driven by necessity rather than choice. For India, the question is stark: move early and help shape the ecosystem, or arrive late and import solutions at a premium.
Cast magnesium wheels, followed by targeted applications in electric motorcycles, offer a pragmatic and strategic entry point. OEMs and suppliers that begin asking the right questions about magnesium today will be the ones defining vehicle platforms tomorrow. Magnesium is no longer a footnote in automotive materials; it is fast becoming the headline.
Disclaimer: Views and opinions expressed in this article are solely those of the original authors and do not represent any of The Times Group or its employees.
