Test Stand Evaluations of Commercial Lubricants with Methanol and Tertiary Butyl Alcohol Blends

With the emergence of oxygenates as blending components in unleaded gasolines in the last few years, concern has been voiced as to the effects these materials may have on the wear characteristics of commercial engine oils. To help define these effects, if any, Atlantic Richfield initiated a program whereby gasoline grade tertiary butyl alcohol and methanol/gasoline grade tertiary butyl alcohol were blended into a base unleaded gasoline at various concentrations and individually tested with several commercial SF engine oils in a series of modified ASTM Sequence VD tests.

Although it is known that neat methanol greatly increases engine wear rates, the tests conducted here indicate that the alcohol blends up to 4.5V% methanol/4.5V% GTBA are compatible with properly formulated engine oils and do not increase wear rates over that of unleaded gasoline. Other parameters such as sludge and varnish were also found to be unaffected or slightly improved with the addition of the alcohol(s) to the base test fuel.