A recent independent test conducted on Amsoil 100% Synthetic 10W-30 Motor Oil, Royal Purple Synthetic 10W-30, and Lucas Synthetic 10W-30 has delivered some dramatic results. The volatility of all three motor oils was tested using the “ASTM D-5800” NOACK volatility test. Explanation:
The NOACK Volatility Test determines the evaporation loss of lubricants in high-temperature service. The more motor oils vaporize, the thicker and heavier they become, contributing to poor circulation, reduced fuel economy and increased oil consumption, wear and emissions. During the test, the subject oil is heated to 150 degrees centigrade causing the lighter oil molecules to boil off. The results are reported as a percentage, by weight, of the oil that evaporates. The lower the number, the better the resistance to vaporization.
This test certainly shows consumers which oils will perform well under high operating temperatures. Oils that are resistant to volatility loss are more apt to stay in their original viscosity grade, reduce consumption and keep engine internals clean. Oils that are susceptible to “boiling off” tend not only to leave behind deposits and sludge, they also lead to thickening, consumption and reduced fuel economy.
To meet current API SM specifications, a motor must not lose more than 15% of its weight in the NOACK test.
AMSOIL has long prided themselves on producing motor oils that perform well in this test. They were using this protocol to test their motor oils long before this method was generally used in the North American market.