What oil should be used in the dampers?
SU will supply specific oil for this purpose. It is essentially 20 weight engine oil. In the pre-war period various types were recommended, such as “Bicycle Oil”. In the 1960’s some OEM installers like Volvo advised ATF. Regardless, the OEM installer and SU designed and adopted the needle profiles according to the oil they recommended. So what happens with other oils? The answer is simple. The higher the viscosity, the more pronounced the enrichment during throttle transitions for acceleration. As well, use of a multi-grade oil will vary the enrichment in the opposite to that needed during warm-up to operating temperature. If the oil selected, be it gear, engine, transmission, sewing, or synthetic, causes no unacceptable symptoms, it is fine. Certainly nothing will be damaged.
