Which to choose Polyurethane or Rubber, Suzanne Keane explains what you need to consider.
A tell-tale knocking sound, an NCT failure or something just not feeling quite right in the steering and handling are all signs that your bushes could be in trouble
So what are they?
Where a metal chassis meets a moving part in your car a bush is required to protect the joint, reduce noise and eliminate vibration. In most vehicles these are made from a rubber compound.
Rubber bushes are cheap to produce and as a soft substance they fulfil the need to reduce noise and vibration. However rubber bushes deteriorate and crack with age so will only last for a couple of years before needing to be replaced.
Buying replacement rubber bushes may be cheap but labour to install them won’t be. If you’re planning on keeping your car for a few years or would like to improve your suspension firmness upgrading to Polyurethane bushes is a worthwhile investment.
Despite the longevity and benefits Polyurethane costs roughly 10 times what rubber costs to buy as a raw material and is more time consuming to process so therefore is uneconomical for manufacturers to use when manufacturing standard bushes.
I’ve been replacing worn bushes in my own cars for years with Polybushes – more specifically Powerflex bushes. You don’t need to replace them all at once either –each bush can be bought separately so you can just replace what’s needed (it’s important that you replace both sides with the same bush at the same time – like with tyres). Most recently I’ve had to replace anti-roll bar bushes.
As an investment Polybushes aren’t expensive – sometimes the cost of a Powerflex bush will be less than a genuine rubber bush from your main dealer – but the real saving is in replacement as they come with a lifetime warranty and therefore should never fail.
High performance bushes also improve your contact with the road and allow for more accurate suspension movements – this can in turn reduce tyre wear, improve handling and reduce the impact that bad roads and potholes will have on your alignment and tracking!
18th May, 2015