Oil Knowledge

The engine oil is exposed to high pressure, resistances and temperatures. It neutralises particulates, acids and water. But even the very best engine oil wears out over time and residues build up, which is why the oil has to be changed regularly.

The oil filter collects combustion residues and the dirt absorbed by the oil in the engine; this all builds up over time. So, it should be changed at the same time. Our Volkswagen Dealers will also change the seals and the oil drain plug.

Compare the specification in your owner's manual with the labelling on the engine oil bottle (VW standard).

A film of lubricant must be guaranteed, even when subject to extreme outside and engine temperatures. The owner’s manual will help you find the right engine oil. Use only Volkswagen Genuine Oil or an oil that has been approved by the manufacturer so your engine stays clean, acidic combustion products are neutralised and the build-up of sludge is prevented.

In general, oils for the same engine concept can be mixed, i.e. different engine oils for diesel engines can be mixed with each other, and different engine oils for petrol engines can be mixed with each other. As such, synthetic oils can also be mixed with mineral-based oils. The engine oil must meet at least the prescribed performance characteristics set out in the VW standard. The quality may also be higher.

Anyone who does not use an approved oil, risks engine damage and generally loses their guarantee. The quality of engine oils is defined by a combination of letters and numbers. The different specifications describe the right oil for your engine concept. So, stick to the manufacturer’s specifications to contribute to a long engine life.

Engine oils differ not only in terms of their properties, but also in terms of their flow properties – the viscosity. This is indicated by the SAE classification from the Society of Automotive Engineers. To ensure that the engine oil matches your engine, it has to have the right viscosity. To select the right oil, make the most of your Volkswagen Dealer’s expertise, they will be happy to assist.

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You can read everything you need to know about the viscosity of engine oil under the SAE classification of the Society of Automotive Engineers found on the oil bottle. It tells you how viscous the engine oil is in cold or warm temperatures, in winter or in summer.

The classification for cold temperatures is made up of a number and a W for winter – e.g. 0W. The classification tells you up to which sub-zero temperatures the engine oil is free-flowing – for example, SAE 0W is -40 °C. The higher the number, the more viscous the oil.

The classification for warm temperatures is just a number. It indicates how quickly the engine oil circulates at 100 °C, i.e. how thin it is.

Most modern engine oils are designed for use in every season, i.e. all-year or multigrade oils.

The number before the W tells you the sub-zero temperatures to which the engine oil remains so liquid that it is still easy to pump. The lower the value, the better the oil circulation in cold temperatures. An SAE 0W engine oil is thinner in cold temperatures, circulates more effectively and lubricates the engine quicker than an SAE 25W engine oil. The SAE classification for pure winter oil consists of a number and a W.

SAE classifications and the temperature at which the engine oil can still flow:

• -40 °C/SAE 0W
  
• -35 °C/SAE 5W
  
• -30 °C/SAE 10W
  
• -25 °C/SAE 15W
  
• -20 °C/SAE 20W
  
• -15 °C/SAE 25W
  

The smaller the number after the W, the thinner the engine oil at 100 °C. This means that, for example an SAE 16 engine oil (kinematic viscosity of 5.6 mm² per second) achieves a greater spread across a surface than a viscous engine oil with SAE 60 (kinematic viscosity of 21.9 mm² per second).

In addition: The slower an engine oil’s circulation, the more stable its film of lubricant.

The SAE classification for pure summer oils is a single number – e.g. SAE 20.