Development and Testing of Crankcase Lubricants for Alcohol Fueled Engines

The 1979 decision by the Brazilian government to confirm their plans for widespread distribution of neat ethanol fuel (100%) to reduce petroleum imports prompted many investigations of the effect of the ethanol on passenger car durability. This paper describes results of a program to develop crankcase lubricants suitable for service with ethanol fuel over a wide temperature range.

Engine wear at low temperatures was found to be the major problem. A low temperature Sequence V-D (PV-1) test previously developed, provided a suitable environment for lubricant evaluation. Service station oils at the API SE and SF quality levels were developed based on consideration of their wear and corrosion inhibition when emulsified with ethanol. They were found to reduce critical wear parameters in the low temperature V-D test. Although vehicles operating in the warm climate of Brazil do not require all of the protection needed to pass the low temperature test, this work provides a useful start for the development of lubricants formulated for other oxygenated fuels such as methanol. Interest in the latter is growing in several areas of the world where temperatures below freezing are prevalent in the winter.