In the race to make vehicles lighter and more efficient, some of the most meaningful changes happen far from the spotlight. One of them is beneath the chassis - the leaf spring, which has steadily evolved, reducing weight, improving functionality, and delivering better performance through the use of advanced composite materials.
Understanding the Significance of Leaf Springs
Leaf springs are vital to vehicle suspension systems, especially in pickups and commercial vehicles, supporting loads, maintaining ride height, absorbing road shocks, and influencing handling and comfort. As part of the unsprung mass, they account for nearly 10–20% of it, meaning weight reduction here directly improves fuel efficiency, ride quality, and vehicle dynamics.
With increasing pressure to reduce energy consumption and enhance efficiency, automotive manufacturers are turning to lightweighting strategies, leveraging advanced materials, optimized designs, and smarter manufacturing. Traditional multi-leaf steel springs are known for their strength, but their high weight, corrosion issues, and fatigue limitations restrict overall performance. This opened the door for composite materials to step in, positioning composites as a higher-performance alternative rather than a substitute.
Steel vs Composite: A Clear Weight Advantage
Composite leaf springs, typically manufactured using fiberglass-reinforced epoxy systems, deliver 60–80% weight reduction compared to steel designs. However, the advantages extend far beyond mass savings.
Composites exhibit higher elastic strain limits, allowing greater deflection under load without permanent deformation. This increased deflection capability improves energy absorption and contributes to smoother ride characteristics. At the same time, composite springs often demonstrate a higher factor of safety due to superior fatigue resistance and more uniform stress distribution across fibers, unlike steel, which concentrates stress at specific locations.
Additionally, composite mono-leaf designs reduce part count, eliminate inter-leaf friction, resist corrosion, and maintain performance consistency over longer service life.
Here’s a standout example showing how composite leaf springs outshine steel ones in performance and efficiency.
Real-World Proof: GM’s Award-Winning Composite Leaf Spring
A standout example comes from General Motors’ 2022 Chevrolet Silverado and GMC Sierra, featuring an all-composite tension leaf spring developed by Mubea. Manufactured using fiberglass-reinforced epoxy prepreg through prepreg layup and compression molding process, this system achieved:
- Up to 75% mass reduction vs all-steel designs
- 58% reduction vs hybrid steel-composite solutions
- Double the durability and corrosion-resistant
- Improved ride comfort, reduced NVH, and increased payload
Notably, the design eliminates shackles, bushings, and helper leaves, yet meets all OEM performance and durability requirements.
Lightweighting That Delivers More Than Weight Savings
The transition from steel to composite leaf springs reflects a larger transformation in automotive engineering, driven by the need for lighter structures, higher efficiency, and longer service life. As these priorities intensify, demand for composite materials continues to rise due to their superior strength-to-weight performance, corrosion resistance, and fatigue durability. As a result, composites are increasingly viewed as strategic enablers of next-generation suspension systems rather than simple material replacements.
From weight reduction to performance gains, discover where the automotive composite leaf spring market is heading. Click here for Stratview Research’s detailed industry report.
TAGS: Composites Automotive