Italian auto parts maker Sogefi and Volkswagens Audi have jointly developed new suspension spring technology which will result in more precise driving and lighter parts, Sogefi said on Thursday. Sogefis shares rose more than 3 percent on the news, and were up 2.6 percent at 4.09 euros by 1333 GMT, outperforming a 1 percent rise in Milans All-Share index. The new suspension springs, based on a technology patented by Sogefi, will be made from a glass fiber-reinforced polymer instead of steel and will weigh between 40-70 percent less than traditional steel springs, the company said. They can be assembled on cars and light commercial vehicles without affecting the suspension system architecture, allowing for a weight reduction of 4-6 kg (8.8-13 lb) per vehicle, it added.