Piston Ring Sets: for Audi engines. AUDI: 100, 200, Quatro, 80, 90, A3, A4 ... Q5, Q7, etc United Material Piston Rings: for Audi Engines Compression Ring | Intermediate Ring | Oil Ring We offer ... original equipment quality as well as for older engines with the aim of reducing their compression loss ... that are suitable for all types of combustion engines with cylinder diameters of 30 to 238mm. They ...