22 June 2026
Speak to one of our experts.
Speak to one of our experts.
9 July 2026
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Advice Blog
When you’re upgrading your suspension bushes, it’s natural to ask one question before anything else: which hardness should I choose?
At Polybush, we manufacture polyurethane bushes in different material grades to suit different vehicles, driving styles and applications. Whether you’re restoring a classic car, improving the handling of your daily driver or building a dedicated track car, selecting the right material can make a noticeable difference to how your vehicle performs.
However, you won’t always see multiple hardness options listed on our website.
That’s entirely intentional.
If we don’t offer a choice of hardness for a particular bush, it’s because we’ve already selected the material that delivers the best balance of ride comfort, handling, durability and longevity for that specific suspension location. Every product is developed with the vehicle’s suspension design in mind, so you can order with confidence knowing we’ve already done the engineering.
Polyurethane hardness is measured using the Shore A scale. In simple terms:
It’s easy to assume that harder is always better, but that’s rarely the case.
Every suspension bush has a specific job to do. Some locations need more compliance to allow suspension articulation and absorb vibration, while others benefit from a firmer material to maintain suspension geometry under cornering, braking and acceleration.
That’s why we don’t use a one-size-fits-all approach.
One of the most common questions we receive is why some vehicles are available in Comfort, Dynamic and Performance grades, while others only come in a single material.
The answer is simple: vehicle suspension has changed dramatically over the last 50 years.
Classic cars and older Land Rovers were designed around relatively soft rubber bushes. At the time, suspension relied on a significant amount of bush movement to deliver ride comfort and allow the suspension to work effectively. Take a Jaguar E-Type as an example. The original rubber bushes were considerably softer than the bushes found on most modern vehicles, because that’s exactly what the suspension was engineered around.
Today, suspension design is very different.
Modern cars are generally heavier, faster, more powerful and capable of generating far greater braking and cornering forces. Manufacturers have also developed much more sophisticated suspension geometry with far tighter tolerances than older vehicles.
As a result, the original rubber bushes fitted to many modern vehicles are already significantly stiffer than those fitted to classics. Although manufacturers still use rubber due to the ease of manufacturing in volume, rather than polyurethane, the stiffness of those bushes is often comparable to our firmer polyurethane compounds.
It isn’t unusual for an everyday modern hatchback with a modest engine to require a bush equivalent in stiffness to our 85A Performance material, simply because that’s what the suspension was designed to use.
That’s why you’ll often find we offer multiple hardness options for classics and Land Rovers, allowing owners to choose between originality, improved road manners or outright performance.
For many newer vehicles, however, there’s simply no benefit in offering softer alternatives. We’ve already selected the material that best matches the vehicle’s original suspension design, ensuring it performs exactly as intended while providing all the durability advantages of polyurethane.
Our Comfort bushes are designed for drivers who want to preserve ride quality while enjoying the long-term durability of polyurethane.
Manufactured from 65 Shore A polyurethane, these bushes provide the greatest suspension articulation while absorbing bumps, vibration and road noise more effectively than firmer materials.
They’re especially popular on:
Comfort bushes retain much of the relaxed, compliant feel associated with factory suspension while lasting significantly longer than traditional rubber.
Our Dynamic grade offers the ideal middle ground.
At 75 Shore A, these bushes are firmer than Comfort, reducing unwanted suspension movement to improve steering precision and cornering response, while remaining comfortable enough for everyday driving.
For many enthusiasts, this represents the perfect balance between comfort and performance.
Dynamic bushes are equally suited to the daily commute, spirited weekend drives and occasional track days.
For drivers demanding maximum precision, our Performance bushes deliver the highest level of control.
Manufactured from 85 Shore A polyurethane, these bushes minimise suspension deflection, helping maintain accurate suspension geometry under heavy cornering, hard braking and acceleration.
The result is:
Although they naturally transmit a little more road feel than softer compounds, they’re the ideal choice for drivers who prioritise precision above outright ride comfort.
Alongside our suspension bushes, we also manufacture machinable polyurethane rod.
Produced in 90 Shore A polyurethane, this material has been specifically formulated for machining on a lathe, making it suitable for producing custom bushes, mounts and specialist engineering components where durability and dimensional stability are essential.
Replacing worn rubber bushes with Polybush polyurethane bushes isn’t simply about making your suspension firmer.
It’s about fitting a material that’s engineered to perform consistently for years to come.
Unlike conventional rubber, polyurethane is highly resistant to:
This means your suspension maintains its performance for significantly longer instead of gradually deteriorating as rubber naturally ages.
Every Polybush bush is designed as a direct replacement for the original component, making installation straightforward while delivering consistent, predictable performance.
Not all polyurethane bushes are created equal.
Every Polybush product is manufactured in the UK using our own specially developed polyurethane formulations. Each compound has been engineered to provide the correct balance of comfort, durability and handling for the application it’s designed for.
Unlike many polyurethane bushes on the market, Polybush bushes are also dry-fit, meaning no grease is required during installation. That eliminates one of the most common causes of squeaking while making fitting cleaner and easier.
When you choose Polybush, you benefit from:
If your vehicle offers multiple material options, choosing the right one depends entirely on how you use it.
Comfort (Blue – 65A) is ideal for owners wanting to preserve the original ride quality of classics, Land Rovers and touring vehicles while benefiting from the longevity of polyurethane.
Dynamic (Orange – 75A) provides an excellent balance between comfort and sharper handling, making it perfect for enthusiastic road driving and lightly modified vehicles.
Performance (Red – 85A) is designed for drivers seeking maximum precision, whether that’s on track, on fast road drives or when towing heavy loads.
If your chosen bush doesn’t offer a choice of hardness, there’s no need to second-guess it.
We’ve already selected the polyurethane compound that best suits that particular suspension location based on years of engineering, testing and real-world experience.
Our aim has never been to offer the greatest number of options. It’s to provide the right material for every application.
Whether you’re restoring a cherished classic, maintaining a hardworking Land Rover, refreshing the suspension on your daily driver or improving the handling of a modern performance car, Polybush offers a suspension bush that’s engineered for the job.
Every bush is manufactured in the UK, built to last and developed to improve the way your vehicle drives without compromising what makes it enjoyable in the first place.
Because the best suspension bush isn’t always the hardest one. It’s the one that’s been engineered and manufactured specifically for your vehicle by people who care.
