There are myths suggesting that the problem is caused by 'cheaper metal', speed humps or over-loading but the simple fact is that springs are lighter, thinner and don't cope as well with salt and rust.
With bigger/wider wheels fitted, the tyre sidewall on a modern car is much closer to the spring and if the spring breaks, tyre damage is likely too.
A plastic coating is applied to coil springs when they’re made but contact between coils as the spring is repeatedly compressed in service can damage this coating.
- Salt on winter roads can accelerate the corrosion process.
- Breakdown clubs in Italy, Portugal and Spain haven’t seen an increase in the number of coil spring failures but the German club, ADAC has. Roads aren't salted in winter in southern European countries.
- Some car manufacturers fit 'spring catchers' to try to limit the damage caused when a spring breaks.
- The amount of energy trapped in the spring makes it almost impossible to predict the way they’ll break so spring catchers won’t always work.
- Fitting spring catchers adds a fair bit to the cost of assembly too.
A regular clean underneath your car with a hose or pressure washer during winter and early spring might help extend spring life.