2.15.7. Specification of engine oil

In modern engines use of HD oils is allowed generally. HD oils are the alloyed oils which lubricant properties, thanks to additive of various chemicals are considerably improved.

These additives provide the best protection against corrosion, increase resilience to oxidation, to formation of dregs in an engine case, improve viscous properties, have properties to clear and dissolve. Additives for clarification and dissolution reduce not only formation of a deposit in the engine, but also have ability to dissolve a deposit and it, together with other pollution, to dismember on the smallest particles and to support them in suspension so when replacing oil they merge together with oil.

Quality of HD oil is given in the API system (API: American Petroleum Institut). Designation is given by two letters. The first letter specifies a scope: S = service, is suitable for petrol engines; With = commercial, is suitable for diesel engines. The second letter specifies quality in alphabetical order. The superior quality in the API system SG specification oils for petrol internal combustion engines and CD for diesel engines have.


The CD engine oils designated by the producer as oils only for diesel engines, do not approach petrol engines. There are oils which approach both to petrol and diesel engines. In this case both specifications are designated on packing (for example: SG/CD).

VW A.G. established the oil norms for models of the VW cars. Oils which meet these standards have to be applied. If there is a doubt, then about the oils allowed for use it is possible to cope with sales representatives.

For petrol engines the oils working at big loading which have to answer two norms of VW 50000 and 50500 at the same time are required. Very fluid oils of norm VW-50000 or all-weather oils of norm VW-50101 can be also applied. The all-weather oils meeting standard of VW-50101, as a rule, are more expensive. If near at hand there is no oil of this specification, it is possible to use temporarily seasonal or all-weather oil of the API-SG specification.

In diesel engines engine oils of the specifications VW 50101, VW 50500, API-CD or very fluid VW 50000 oils can be applied.