Audi Suspension Springs Are Trading Steel for Composites

Forget what you know about car suspension: Audi is tearing up the rule book and making its latest springs from glass fiber-reinforced composite instead of steel. It's not gone mad, though; this is the future.

The new springs , pictured on the left, are made of thin glass fibers held together in epoxy resin. A machine—which I would really love to see in action—twirls fibers around a small central core at plus or minus 45 degrees to the direction of the coil. Its then coated in epoxy and cured at around 100 degrees Celsius.

The resulting springs feature a larger diameter spiral than their steel siblings, and their overall diameter is bigger too. So what's the point?

Weight, my friend. And lot's of it. While a steel spring for a mid-size car weighs about 6 pounds, these new GFRP coils weigh just 3.5. That's a 40 percent saving, and adds up to 9.7 pounds across the whole car. Sure, that's not a huge overall percentage gain, but it's rare a single component can shed so much weight in one go. Oh, they're also corrosion resistant, too, and require less energy to manufacture.

The new springs will feature in at least one of Audi's mid-sized models before the end of the year. [Audi]