Polyurethane vs Rubber Bushings (Benefits & Drawbacks)
Updated: Nov 6, 2021
Car bushings are suspension pieces that decrease friction between your vehicle's metal sections. They're made of shock-absorbing materials like rubber, and they're essential for a smooth ride.
Bushings are surprisingly basic in design for something that makes such a large impact.
They are made up of just two parts: a pliable inside (usually rubber) and an exterior (typically metal) sleeve. However, they usually need replacing eventually.
When Should Bushings Be Replaced?
There is no standard frequency for bushing replacement since their lifetime varies greatly based on driving style, climate, and other factors. Instead, mechanics advise that you replace them if you detect any of the following symptoms.
Excessive road noise and vibration
Unusual sloppiness in steering and lack of direct control
Knocking, squeaking, or cracking noises coming from the wheel area
Rattling noises coming from the wheel area
The question is; should I choose rubber or polyurethane bushings?
Polyurethane vs Rubber Bushings
Polyurethane bushings (frequently called poly bushes) are used primarily as an aftermarket replacement, they're not common in OEM vehicles.
Rubber bushings are the most common and usually the most comfortable type of bushing.
More vibration and road feedback
Less vibration road feedback
More road noise and a chance of squeaking
Less road noise and no chance of squeaking
Lasts the life of the vehicle
Around ~15 years
Requires greasing every 3-5 years
No maintenance required
Improved steering response, more stable, less unwanted movement
Reduced steering response, less stable, more unwanted movement
More road feedback and more direct steering response
More of a floaty feeling with less direct steering and less road feedback
Can be done yourself with the correct tools
Requires professional fitting
More expensive aftermarket
Polyurethane bushings were formerly only accessible to the military and racecars, and it wasn't until around the 1930s that they were commercially available.
They generally outlive the vehicle they're installed on since they don't rust or corrode. Poly bushings are an excellent alternative for anybody wishing to improve their suspension setup for high performance use.
Comfortability: Polyurethane bushings are prone to causing a rough ride because of their hardness. Passengers are exposed to a lot more road noise and vibration since they aren't as excellent at dampening out minor road vibrations.
Hardness: Polyurethane bushings are substantially more durable and harder than rubber bushings. However, this does not imply that they are the most durable or hard. Aluminium suspension bushings utilised by racing drivers are the hardest and most durable with almost zero movement.
Lifespan: Poly bushings have a longer lifespan than rubber bushings because they are more resistant to the demands of the suspension system. They're also UV, oil, chemical, corrosion, and heat resistant. Polyurethane bushings are frequently covered by comprehensive warranties since they often outlive the vehicle they're put on.
Noise: Polyurethane suspension bushings do not have to squeak, contrary to common assumption. It's simply that they're more inclined to do so. It all boils down to how they're constructed. Rubber bushings are chemically linked to their housings, while poly bushings are manually joined. They have space to move and rub against their sleeve as a result. This may cause some squeaking noises if not properly maintained.
Installation: Installing a polyurethane suspension bushing does not normally need the use of a hydraulic press. Removing an old rubber bushing may be difficult, though.
Maintenance: Unlike rubber suspension bushings, poly suspension bushings must be lubricated and greased every 3-5 years.
Feel & Performance: Polyurethane bushings make the car feel like an extension of the driver. The road gives more feedback to the chassis and steering. This improves the feel of the car for high performance cars and drivers. It helps to remove unwanted suspension movement and flex.
Price: Poly bushings are the least expensive aftermarket.
Rubber is much more malleable than polyurethane, making it an excellent bushing for individuals who want a little extra comfort in their car. It's also what most automobiles come with as standard equipment.
These types of bushings are more suited to regular cars and for those who aren't after high-performance suspension setups.
Comfortability: Rubber is significantly better at absorbing road noise and vibrations than polyurethane because it is softer. As a result, rubber bushings provide a significantly smoother ride. Aside from cost, this is one of the key reasons why OEMs utilise rubber ones in the assembly line.
Hardness: Rubber is far more malleable than polyurethane in terms of hardness.
Lifespan: Rubber suspension bushings have a substantially shorter lifetime than polyurethane suspension bushings. They're also more vulnerable to oil, UV, chemicals, and heat damage. The forces of the road cause rubber to twist and stretch over time. Sometimes they may only last 3-5 years, if the car is not used regularly, they may last 10-15 years.
Noise: When bushings scrape against their metal housings, squeaking ensues. There is no room for movement since rubber bushings are chemically bound to their shells. They'll never squeak as a result of this.
Maintenance: Rubber bushings are completely maintenance-free, with the exception of eventual replacement.
Installation: Rubber bushing installation is more difficult than poly bushing installation. It generally necessitates the use of a hydraulic press and the removal of the afflicted springs or control arms entirely. Hydraulic presses aren't often seen in backyard mechanic shops, so installation is best left to the professionals.
Feel: If you replace your old rubber bushings with new ones, the road should feel similar to how it did before they failed. It reduces feedback from the road, making the car more floaty feeling and comfortable.
Performance: When you pick rubber bushings, you're choosing comfort over performance. Rubber provides a smoother ride than polyurethane because it has a lot more flex. However, the extra suspension movement makes the steering less direct.
Price: Rubber bushings are more costly aftermarket, although being provided at a discount to OEMs.