The automotive suspension market is worth over $53 billion worldwide. It’s clear why: a vehicle’s suspension has an outsized impact on its performance.
Studies demonstrate a suspension’s design alters how an auto runs in wildly diverse ways—from quantifiable effects on brake time, strength, fuel efficiency, stability, and parts’ longevity, to vital-yet-subjective qualities: how cool a truck looks, or how comfortable it is to ride in it.
Consider handling. The average semi-active suspension improves a vehicle’s handling over passive suspension by up to 51%. Moreover, it boosts performance across all stability and reaction time metrics.
For commercial vehicles, in particular, suspension modifications are worthwhile investments. But, not all upgrades are equally useful or effective.
In this guide, our experts unpack how to upgrade a car or truck's suspension, weigh attributes of different suspension mod options, and explore how to choose the right upgrade for your ride.
How To Upgrade Suspension: Overview & Definitions
A vehicle’s suspension system mutes the impact of contact forces on passengers and cargo, keeping the ride smooth and the vehicle stable.
Functionally, the suspension absorbs shocks sent by the wheels’ contact with the road; it also controls their angles and alignment. It’s situated between the car’s chassis and steering system for optimal cushion and balance.
To learn about these systems’ specific parts in greater detail, check out our guide to heavy-duty truck suspension systems. When it comes to upgrades, suspensions are classified along three spectrums.
Independent Vs. Dependent Suspension Systems
Independent suspension systems enable each wheel to move individually. A wheel’s motion and reaction to the road doesn’t directly affect any other wheel.
Dependent suspension systems link wheels in pairs on an axle. Both wheels in a pair move simultaneously, and each directly affects its opposite.
Semi-independent systems often link wheels, but the design offers some autonomy of movement to each wheel.
The more independent a system is, the more precisely it can handle, and the more shocks it can effectively absorb. Dependent systems offer weaker performance, but they’re less expensive.
Passive Suspension Vs. Active Suspension Systems
Vehicle suspension systems can be passive, semi-active, adaptive, and active.
Passive Suspension
Passive suspension systems use components with unchanging physical dynamic traits. Typically, these systems incorporate a wishbone, spring, and damper. The spring’s firmness and the damper’s damping force ratio are constant.
Engineers aim to set the levels of a passive suspension system to reduce vibrations and enhance road holding. But, because the traits are fixed, these suspensions cannot adapt to different road conditions.
Semi-Active & Adaptive Suspensions
Semi-Active and adaptive suspension systems offer more feedback control than passive suspensions.
Rather than simply reacting to the road with a fixed level of force or firmness, semi-active systems change the shock absorbers' damping force ratio in response to different driving conditions.
Most adaptive systems control valves or magnets integrated into a fluid (air or hydraulic) suspension. Unlike active suspensions, adaptive systems can only alter the damping dynamic, while active systems can alter multiple traits.
Active Suspension
Active suspension systems can adapt to different conditions by altering the height of the vehicle’s chassis and floor through actuators, changing the damping force (including air spring rate), and adjusting the wheel camber.
These systems use a sophisticated, onboard software program and numerous, accurate sensors to continually receive data—information updates on the environment, internal systems, and how the vehicle is handling. Then, the system responds to the ongoing data input in real time.
Using precise, robotic controls, it adjusts the vehicle’s suspension automatically.
Truck Vs. Car Suspension Upgrade
While suspension systems in cars and trucks are functionally similar, it's wise to seek out certain features when upgrading a heavy-duty vehicle.
Better Suspension, Better Performance: Suspension Upgrade Considerations For HDVs
Certain suspension system features are more relevant to drivers of heavy-duty vehicles than they might be to others. Consider these traits.
Component Strength & Durability
Heavy-duty applications can damage or even break suspension parts not designed for the task. Choose suspension upgrades built with strong, resilient parts for HDV use.
Ground Clearance
Heavy-duty vehicles often need to maintain a specific degree of ground clearance to drive off-road or over rough terrain safely. Any suspension upgrade should maintain the necessary degree of lift, which may be higher for your HDV than for a regular car.
Sway Bar Size
HDVs face a higher risk of body roll when cornering. Effective sway bars will have a large enough diameter to enhance stability safely.
Tire Size & Alignment
Any suspension upgrade, no matter how minor, must be aligned with your vehicle’s other systems and frame to function. Choosing the correct size is crucial.
Damping Force
Commercial heavy-duty vehicles need suspension components that exert greater damping force than a car's shocks to maintain stability and an effective cushion. Any given shock absorber, damper, or strut exerts a different amount of damping force depending on how fast the engine's going.
Look for shock-absorbing components with variable or adaptive damping, or for those with valve designs compatible with HDVs.
Adjustability
Adjustable or adaptive suspension systems can be altered to function better in different conditions. Choose automatic or manually adaptive suspensions if you want the option to alter the air spring rate or tire camber in response to different environments.
5 Best Suspension Upgrade Options: Purposes, Pros & Cons
Drivers often find these options among the most useful suspension upgrades on the market. Consider the benefits and costs of each before choosing one for your ride.
1. Best Overall: Active Air Suspension
When it comes to performance, safety, and fuel efficiency, active air suspension systems are best in class.
Air suspension systems cushion and absorb shocks through flexible rubber bellows filled with compressed air, rather than springs or coils. Drivers can control the air pressure in the bellows via an electric pump. This degree of control makes air suspension an intriguingly active, adaptable system.
Benefits
Adapt To Diverse Terrain & Cargo
Air suspension systems empower trucks to adapt more readily to different types of terrain. Drivers can adjust air pressure levels to clear rocky terrain or better handle challenging roads by enhancing grip. They can also adjust the control valves to compensate for uneven loads, or to offer greater cushion to fragile loads like glass.
Ride Comfortably
Air suspension systems demonstrate the most positive impact on driver wellbeing, according to public health authorities.
Active air ride suspensions reduce how often and how intensely truck drivers experience whole body vibration by 55%—curtailing a significant cause of back pain and injury. In contrast, passive suspension systems only reduce WBV frequency and severity by 5%. Air-filled cushioning systems also reduce driver fatigue by 14% more than foam-and-spring systems.
Increase Longevity of Tires & Truck Parts
Air suspension systems dramatically reduce noise and vibrations. This muffling and cushioning eases the strain on tires and significantly slows down the rate of wear and tear on the vehicle’s parts.
Costs
Expensive
While a basic air-ride suspension kit for a light-duty truck starts at around $1000, air suspension installation for a heavy-duty truck starts at $2000–and that price tag can run over $5000 for higher-end upgrades with parts fabricated to order.
Complex Operations & Maintenance
Mastering the skill of operating an air suspension system takes time and practice; it isn’t intuitive. Maintaining an air suspension system takes more time than you’d spend on other systems.
2. Best For Increased Load Capacity and Durability: Leaf Spring Suspension
A leaf spring suspension is a passive, dependent system. It's a series of arc-shaped plates attached to the vehicle’s axle and chassis; the plates flex vertically in response to irregular contact force from bumpy roads or potholes. They also make it easier to raise or lower a truck.
If you're looking for peak handling or adaptability, it's not the right choice.
Instead, a leaf spring suspension trades optimal control for durability, strength, and easy maintenance. It's a popular choice for truck drivers looking to increase their load-bearing capacity without spending too much.
Affordable, High-Capacity, But Uncomfortable
Leaf springs are made from durable steel materials, and they're cost-effective. Depending on the model and size, a leaf spring might cost as little as $115 or as much as $739. Installation is quick, so it rarely costs more than $200–and it's often less.
But, compared to other suspension modifications, leaf springs don’t offer as much cushion or vibration suppression. As a result, the ride is less comfortable, and it may not be as stable as trucks with other suspensions.
Mono Leaf Vs. Multi Leaf
Mono-leaf suspensions use only one leaf spring, while multi-leaf systems stack and layer leaf springs.
Multi-leaf suspensions can carry higher-weight loads; each additional leaf adds a layer of support, increasing the vehicle's load-bearing capacity by 500-700+ pounds, on average.
But, layering leaf springs compounds the spring stiffness and increases friction. This creates a harsher ride, with less cushion and greater wear-and-tear on the HDV’s parts.
Mono-leaf suspensions are more comfortable, as they reduce vibrations more effectively. They also enhance handling performance more than multi-leaf suspensions do, as they’re more flexible.
3. Best For Enhanced Handling & Body Roll Reduction: Upgraded Shocks & Struts
All vehicles have either shocks or struts, and many use both. These components functionally work to maintain a vehicle’s level and stability by regulating the suspension’s movement, while absorbing contact forces during a drive.
Upgrading to high-performance shocks and struts can increase the damping of vertical suspension motion, which reduces vibration and, indirectly, improves balanced weight distribution. Modified shocks can also absorb the higher shock forces dealt to trucks on rocky terrain or with heavy loads.
Struts enhance tire contact with the road, improving traction. They also reduce nosedive when braking, decrease stopping distances, extend tire life, and prevent accidents.
Passive & Adaptive Options
Shock absorbers and strut assemblies can be passive, or they can be designed for integration into a semi-active (adaptive) suspension system. Assemblies are independent, though they can function with dependent suspension designs. Shocks are positioned behind the wheel, while struts are integrated with the suspension, typically on the front axle.
Shock & Strut Upgrade Costs
Shock and strut modifications are medium-priced upgrade options. They're more expensive than the most affordable options, like leaf springs, but they cost much less than air suspension systems.
Shock and strut assembly costs vary widely, due to differences in materials and design. Low-end assemblies cost $150 - $300, while premium assemblies cost $800 - $900. Professional installation and labor costs, including wheel alignment, typically range from $150 to $400.
Benefits of Different Shock & Strut Options
OE Shocks & Struts
OE shocks and struts are designed to fit your specific model of truck or car. They’re optimized for your vehicle’s weight distribution and suspension system. As a result, they’re well-suited to improve handling and reduce wear and tear. However, the degree of enhancement they offer is typically lower than high-performance shocks and struts.
Performance Shocks & Struts
Performance shocks are designed with a greater capacity to absorb vibrations and suspension bounce than typical shocks. They work readily with larger tires, lifted trucks, and high-heat generating systems. High-performance shocks and struts also typically have greater durability, resulting in a longer lifespan.
Strut Tower Braces
Strut tower braces connect the vehicle’s front strut towers (positioned on the front axle), to distribute pressure more evenly across the chassis. This redistribution improves stability, and it reduces body flex and twisting. As a result, a truck is easier to handle, particularly when cornering.
Strut tower braces are also called shock tower braces or strut bars.
4. Best For Increased Stability & Steering Precision: Sway Bars (Anti-Roll Bars)
A sway bar, also called an anti-roll bar or torsion bar, increases a suspension’s roll stiffness. It enhances a truck’s ability to resist rolling during turns.
Torsion bars increase roll resistance by connecting front and rear wheels with a torsion spring. The more conventional sway bars are u-shaped steel bars connected to the truck’s two front wheels. Both configurations and designs improve stability when a truck’s weight shifts or when it turns to one side.
Anti-Roll Bar Benefits
Sway bars help keep trucks upright and steady. The pressure redistribution reduces wear and tear on the truck by alleviating its pressure points, and it improves handling.
It also improves safety by decreasing accident frequency. In one study, a torsion bar integrated into an independent suspension decreased stopping distance by 23%. This is a similar rate of stopping distance reduction as automatic emergency braking—technology that reduced injury-causing accidents by 56%.
Sway Bar Costs
Sway bars are an affordable upgrade for most drivers. A sway bar link costs $125 - $160, while a complete sway bar costs $200 - $300.
5. Best Affordable Customization & Handling Improvement: Lowering Springs (Coilovers)
Some of the most popular suspension upgrades for trucks and heavy-duty vehicles are lowering springs. Upgrading to lowering springs means replacing the springs in your truck's suspension with shorter, stiffer (firmer) springs.
Ultimately, lowering springs reduce a vehicle’s ride height.
Coilovers are the most widely used lowering springs for these kinds of upgrades. Most lowering springs are passive, but coilovers are somewhat adaptable, and can be adjusted to change the ride's height as needed,
Coilovers For Ride Height Reduction
Coilovers are coil springs wrapped over shock absorbers in an all-in-one component. A coilover is adjustable, and it offers a high rate of shock absorption. It offers far greater damping than other lowering spring options.
Benefits of Lowering Springs (Coilovers)
Lowering springs drop a truck’s center of gravity, which improves its stability and reduces body roll. The low center also increases the truck’s traction on the road, which in turn increases handling performance.
Lowering springs give autos a mild fuel efficiency boost, as they reduce air drag.
Drawbacks
Lowering springs can increase the risk of bottoming out, and it increases uneven wear on tires. They’re generally less comfortable, and they’re often impractical on rough terrain.
Costs: Typical Lowering Springs Vs. Coilovers
Typical lowering springs are highly affordable. Most kits cost around $100 - $300. Professional installation can take as little as two hours, though complex options may take up to eight.
Coilover conversion costs vary widely, depending on the specific performance metrics and specifications you need. The lowest-end options cost about $270, but the majority of kits are priced between $740 - $2900.
Professional coilover conversion takes 4-6 hours on average.
Upgrade Your Suspension With Point Spring
Choosing the right suspension system for your car or truck boosts its performance phenomenally. Whether you want to optimize your HDV’s shocks, or upgrade to an active system, our certified technicians will get the job done right.
To work with Point Spring & Driveshaft Co. on your auto’s mods, contact us by calling 888-787-7746. Or, fill out the form below, and one of our experts will reach out to you.