This page lists the recommended fluids and lubricants for the S2. Use of anything else can seriously shorten component life and amass large repair bills so it is wise to heed this info ! I know of a few S2 Coupes which suffered premature steering rack failures because a previous owner had used the wrong hydraulic fluid.

Engine Oil - 100% Synthetic Multigrade 5W/40 (or 10W/40 - advisable on high mileage cars). VAGs own 'Synta Gold' product is often the least expensive oil of this type.

Coolant - VAG's own glycol based G11 was originally specified, but G12 can be used on a freshly flushed system. Alternatively, 'G11plus' can be mixed with either G11 or G12.

Brake & Clutch Fluid - DOT4

Hydraulic Fluid - VAG item only - G002000. There is no aftermarket substitute for this stuff. It is cheap from Audi.

Gearbox - VAG synthetic G50 (SAE 75W/90) with special additive

Rear Differential - VAG synthetic G50 (SAE 75W/90) with special additive