On cars manufactured up to April, 1989, the power steering fluid is Dexron II® ATF. Beginning in April, 1989, the power steering fluid was changed to a special hydraulic oil. This fluid, part no. G 002 000, has a very stable viscosity over a wide range of temperatures and is especially suited for use in colder climates. It is fully compatible with ATF. Volkswagen recommends refilling all power steering systems with hydraulic oil G after performing work that requires draining the fluid.