What is the evaporation loss of engine oil?

Lubricants evaporate at high temperatures. Volatile components of the base oil become gaseous, which in turn leads to a thickening of the oil. This changes the viscosity and the lubrication behaviour of the oil.

Evaporation loss is an important quality criterion, especially for engine oils. A high evaporation loss inevitably leads to higher oil consumption and more frequent oil changes. If the oil changes its viscosity and thickens, it can no longer transfer the optimum lubrication properties to the friction partners. The result is an increased energy demand and the associated rise in fuel consumption. The thickening of the oil also promotes sludge formation in the engine compartment. An engine oil with a low evaporation loss is therefore desirable.

The evaporation loss also plays an important role for industrial lubricants. It is therefore a quality feature for chain lubricants in the high temperature range.

How is the evaporation loss of oil measured?

The evaporation loss is determined according to DIN 51581 with the NOACK evaporation test. The NOACK value is given in percent (%). This is used to determine the percentage weight loss of the oil in a standardized test procedure. In the NOACK test, the oil sample is heated to 250 °C and exposed to a constant air flow. After a period of 60 minutes, the mass of the sample is measured to see how much mass has evaporated. The test is based on the operating conditions for engine oil. Similarly, high temperatures prevail at the piston ring and the oil is confronted with blowby gases.

What evaporation loss does engine oil normally have?

Many car manufacturers and the ACEA organisation set limit values for the evaporation loss of engine oils. These are regulated in the individual specifications. Modern engine oils have evaporation losses of approx. 5-13%.

Only NOACK values of oils of the same SAE class can be compared. If, for example, one compares two SAE class 5W30 engine oils, the lower NOACK value of an oil can speak for its quality. The comparison of NOACK values of oils of different SAE classes is not meaningful.

Examples of lubricants by ADDINOL

ADDINOL offers many special oils with a particularly low evaporation loss to keep the viscosity of the oil stable for as long as possible. We have collected some examples of our oils, which have a low evaporation loss and are well below common limits.

ADDINOL oilEvaporation loss after NOACK
ADDINOL SEMI SYNTH 10409.0 (limit value according to ACEA standards 13.0, MB standards <10.0)
ADDINOL SUPERIOR 0409.7 (limit value according to ACEA standards 13.0, MB standards <10.0)
ADDINOL GIGA LIGHT MV 0530 LL9.9 (limit value according to ACEA standards 13.0, MB standards <10.0)


Mayka Nehrkorn

Product Manager Automotives