Hvad er fordampningstabet af motorolie?

Smøremidler fordamper ved høje temperaturer. Flygtige komponenter i basisolien bliver gasformige, hvilket igen fører til en fortykkelse af olien. Dette ændrer viskositeten og smøreopførelsen af ​​olien.

Fordampningstab er et vigtigt kvalitetskriterium, især for motorolier. Et højt fordampningstab fører uundgåeligt til højere olieforbrug og hyppigere olieskift. Hvis olien ændrer sin viskositet og tykner, kan den ikke længere overføre de optimale smøreegenskaber til friktionspartnerne. Resultatet er et øget energibehov og den dermed forbundne stigning i brændstofforbrug. Fortykningen af ​​olien fremmer også slamdannelse i motorrummet. En motorolie med et lavt fordampningstab er derfor ønskelig.

Fordampningstabet spiller også en vigtig rolle for industrielle smøremidler. Det er derfor en kvalitetsfunktion til kædesmøremidler i det høje temperaturområde.

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 CHAIN LUBE XHT 3000<1,5 %
ADDINOL CLIPTEC XHS 150 HT<2 %
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)

Contact

Sven Köhler

Product Manager Automotives / Gas Engine Oils