The spring, reportedly an industry first, is manufactured using a Epikote epoxy resin / Epikure curing agent composition. 

The suspension spring patented by Sogefi, has been in commercial production for the new Audi A6 Avant 2.0 TDI ultra (140kW) since late 2014. Compared with traditional technology, this novel composite spring trims 4.4 kilograms from the A6 Avant 2.0, affording lower fuel consumption. It is also designed to improve driving precision and comfort.