Marelli wins SAA Lightweighting Award for game-changing LeanExhaust

Marelli, the global mobility technology supplier, has secured the prestigious Innovations in Lightweighting Award from the Society of Automotive Analysts (SAA) for its pioneering “LeanExhaust” system. The accolade was conferred at the 9th Annual Materials Innovation Summit in Auburn Hills, Michigan, on 13 November 2025, underscoring the company’s continued leadership in sustainable automotive engineering.

Presented annually, the SAA Innovations in Lightweighting Award honours suppliers whose technologies advance the industry’s pursuit of mass reduction—whether achieved directly or through indirect efficiencies—bringing the sector closer to its sustainability and performance targets.

Marelli’s LeanExhaust represents a significant leap forward in exhaust system design for vehicles equipped with Internal Combustion Engines, including hybrid applications. Compact, lightweight and cost-effective, the system has been engineered to satisfy carmakers’ mounting demand for weight and volume reduction without compromising emissions or acoustic performance. Indeed, LeanExhaust delivers an impressive 16 kg reduction compared with conventional exhaust assemblies, while either exceeding or matching current standards for noise suppression and emissions control.

Crucially, its optimised design and streamlined manufacturing processes enable a 52% decrease in carbon emissions associated with production when compared with typical exhaust systems. This translates to a notable 85 kg reduction in CO₂ output per vehicle for every LeanExhaust system deployed.

At the heart of this innovation are two modular components—a dual-layer converter and a micro-hole design muffler—each engineered to drive meaningful reduction in mass and package size.

The dual-layer converter unites a three-way catalytic converter and a gas particulate filter into one compact unit, cutting the weight of the component by 45% and shrinking its volume by 46%. Beyond its lightweighting credentials, the architecture enables the catalyst to reach optimal operating temperature quickly after cold-start, and maintain thermal stability during electric drive phases in vehicles with engine stop functions. This ensures compliance with the stringent thermal and noise-control requirements of hybrid and electrified powertrains.

Complementing this is the micro-hole design muffler, which utilises a micro-perforated central tube and a series of baffle plates to eliminate the need for the non-recyclable glass wool traditionally used in mufflers. This innovation secures a weight reduction of up to 27% and a volume decrease of up to 15%, while still delivering noise-reduction performance on par with conventional systems. Furthermore, the design permits the use of thinner-gauge stainless steel, bolstering durability and enhancing recyclability.

By consolidating multiple functions and embracing advanced materials and architectures, LeanExhaust offers automakers a streamlined, easily adaptable solution that is expected to provide consistent cost advantages over traditional systems. This philosophy aligns seamlessly with Marelli’s broader platform-based strategy, which supplies carmakers with highly pre-developed, customisable technology sets that simplify development, reduce costs and accelerate time-to-market. The Lean platforms, in particular, are conceived to be sustainable, accessible, launch-ready and carefully tailored to purpose, with fewer components and maximum efficiency at their core.

“We are truly honoured to receive the Innovations in Lightweighting Award for our ‘LeanExhaust’ platform. This recognition is a testament to the dedication and creativity of the entire team in Marelli’s Green Technologies business, who continue to challenge the boundaries of sustainable mobility” stated Shuji Kobayashi, President of Marelli’s Green Technologies business. “LeanExhaust sets a new benchmark in exhaust system design and manufacturing. Through its breakthrough dual-layer converter and micro-hole design muffler, the system delivers substantial weight savings of 16 kg over conventional alternatives, with outstanding performance for emissions reduction, noise control, and overall durability. The system also enhances recyclability, offering our customers a truly future-ready solution.”

In addition to its headline accolade, Marelli also earned an Honourable Mention at the SAA Innovations in Lightweighting Awards for its hybrid suspension system featuring electromechanical actuators. Known as the Fully Active Hybrid Suspension System, it employs a pair of actuators to manage front-end dynamics, while the rear wheels utilise two semi-active shock absorbers. By integrating active electromechanical control on the front axle—the most dynamically loaded during braking and cornering—the system precisely targets the area most critical to vehicle behaviour. Compared with hydraulic systems offering comparable functionality, Marelli’s solution achieves a remarkable 57% reduction in weight with no sacrifice in performance or capability.