ABSTRACT
Crankcase engine oils are the most recognizable lubricant in the automotive area. Both individual and commercial consumers identify their vehicle lubrication with the engine oil. Synthetic engine oils have been commercially marketed since the 1960s, but have taken only a small share of the large engine oil market, worldwide. Synthetic-based engine oils exhibit improved viscometric, volatility, and thermal stability properties over conventional petroleum-based oils. Some use an oil sump or reservoir and others use an oil/fuel mix for lubrication. The function of the engine oil encompasses friction reduction, wear reduction, cooling of internal components, and collecting combustion by-products for removal. The expectations for extended engine life by the individual or fleet operator are being reflected in increased awareness for engine oil performance. North American diesel engine oils are predominately used for heavy-duty commercial use. European diesel engine oils are designated for light-duty use or heavy-duty use.
