London (Index Asset Management) 1st May, 2008: This is a fact that polyurethane is the best material for suspension bushes and nylon is probably the worst. Because when a suspension arm moves up and down it does not move only up and down but it describes an arc. Thus an inner track control arm bush will be required to flex in two dimensions at the same time. A metal bush will allow this movement and also a rubber or polyurethane bush.

But as far as a nylon bush is concerned it will allow up and down movement. Also 100% of the arc loadings will be transferred into the arm and the chassis which causes arm flexing that can easily cause premature arm failure. And because nylon has no vibration absorbing characteristics at all, so all vibration is transferred up the already highly stressed arm which is bad for the car health.

Hence, nylon made bushes must be avoided and instead poly suspension bushes, i.e. suspension bushes made up of polyurethane, should be used. In fact smart motorists these days are using poly suspension bushes only because they have a longer working life. These are impervious to petrol and vehicle oil and their most important quality is high resilience.