Coil Spring vs Leaf Spring for Vehicle Suspension: Difference and Comparison

Key Takeaways

1. Design: Coil springs are made of a single looped steel wire wound into a spiral shape. Leaf springs use several steel plates stacked on top of each other and connected.
2. Function: Coil springs provide suspension through compression and expansion of the coils. Leaf springs flex and bend to absorb bumps and road shocks.
3. Performance: Coil springs provide a smoother ride and handle better on turns. Leaf springs are simple, durable, and suitable for heavy vehicle suspension. Coil springs are more common on modern passenger vehicles, while leaf springs are still used for truck rear suspension.

What is Coil Spring for Vehicle Suspension?

Coil springs are one of the suspension systems commonly used in vehicles to provide support so that the vehicle withstands it and absorbs the shock and vibrations from the road. It is a coil-shaped or helical-shaped spring that is made up of steel. 

In this system, one end is connected to the vehicle’s chassis, and the second is connected to the axle or suspension control arm. The suspension system works as follows: if a vehicle crosses or encounters any uneven surface or bumps, the coils get compressed and expanded, providing a smooth ride.

What is Leaf Spring for Vehicle Suspension?

Leaf spring is one of the traditional types of suspension systems used mainly in heavy vehicles. They are commonly found in SUVs, trucks, and heavy-duty vehicles. A leaf spring for vehicle suspension is a stacked layer of flexible metal chips. 

In this system, one end is connected to the vehicle’s chassis and the other to the suspension control arm or the axle. As they are best known for heavy vehicles, they have high load-carrying capacity that helps the vehicle to carry and tow loads. 

Difference Between Coil Spring for Vehicle Suspension and Leaf Spring for Vehicle Suspension

1. Coil spring suspension is a coil-shaped or helical-shaped spring that is made up of steel. While at the same time, a leaf spring suspension is a stacked layer of flexible metal chips.
2. Coil spring suspension is said to be an independent suspension, whereas, on the other hand, leaf spring suspension is said to be a dependent suspension.
3. Coil spring for vehicle suspension administers better flexibility and gives a comfortable ride. While on the other hand, leaf spring for vehicle suspension administers a limited range of flexibility and offers a less comfortable ride.
4. The coil spring for vehicle suspension has multiple springs present in each corner. In contrast, this leaf spring for vehicle suspension incorporates only one or two springs per axle.
5. The installation of coil springs for vehicle suspension has a large size, thus acquiring more space. In contrast, the installation of leaf springs for vehicle suspension has a flat design, thus acquiring less space.
6. The weight distribution in the case of coil springs for vehicle suspension is equal and evenly dispersed, which leads to employing greater stability. At the same time, the weight distribution in the case of leaf springs for vehicle suspension is uneven and unequal, which leads to employ less stability.
7. The load-carrying capacity of coil springs for vehicle suspension is low. In comparison, the load-carrying capacity of leaf springs for vehicle suspension is high.
8. Coil spring for vehicle suspension requires less maintenance; even if there is damage to a single coil, it can be replaced. While on the other hand, leaf spring for vehicle suspension requires more maintenance and if there is damage to a single coil, the complete spring must be replaced. 
9. Coil spring for vehicle suspension has a better off-road performance if compared to leaf spring for vehicle suspension, which has a moderate off-road performance.
10. Coil spring for vehicle suspension provides a better and smooth ride. At the same time, a leaf spring for vehicle suspension provides a rough ride.
11. The price of manufacturing coil springs for vehicle suspension is high, while, on the other hand, the price of manufacturing leaf springs for vehicle suspension is low. 

Comparison Between Coil Spring for Vehicle Suspension and Leaf Spring for Vehicle Suspension

Parameter of Comparison	Coil Spring for Vehicle Suspension	Leaf Spring for Vehicle Suspension
Construction	Coil-shaped or helical shape made of steel	Stacked layers of flexible metal chips
Type	Independent suspension	Dependent suspension
Flexibility	More and comfortable	Limited and less comfortable
Number of Springs	Multiple	One or two
Installation	More space required	Less space required
Weight Distribution	Equal weight dispersion	Unequal weight dispersion
Load-carrying Capacity	Low	High
Maintenance	It can be repaired if the single coil is broken down	It cannot be repaired if a single coil breaks down
Off-road Performance	Better	Moderate
Ride Comfort	Smooth ride	Rough ride
Cost	Expensive	Cheaper

References

1. https://www.researchgate.net/profile/Venkata-Mamilla/publication/303758512_International_Journal_of_Emerging_trends_in_Engineering_and_Development_DESIGN_AND_STRUCTURAL_ANALYSIS_OF_COMPOSITE_MULTI_LEAF_SPRING/links/575113b108ae1f765f9466e7/International-Journal-of-Emerging-trends-in-Engineering-and-Development-DESIGN-AND-STRUCTURAL-ANALYSIS-OF-COMPOSITE-MULTI-LEAF-SPRING.pdf
2. https://pubs.geoscienceworld.org/ssa/bssa/article-abstract/72/6A/2349/118472/The-leaf-spring-seismometer-Design-and-performance