Development of Long Drain Multigrade Diesel Engine Oils for the Canadian Market

Abstract

A line of high-quality multigrade diesel engine oils suitable for long drain applications has been developed using hydrotreated base stock. To meet the growing demand for lubricants in Canada and to offset the high degree of reliance on imports, a new lubricant facility has been constructed in the Toronto area. The facility employs a process in which feedstock undergoes very severe hydrogenation under high pressure. Products are then fractionated, dewaxed, and again hydrogenated under more moderate conditions. Advantages of the hydrotreating process include increased yield, greater flexibility in producing various viscosity grades, and less dependence on selected lubricant crude sources. Two hydrotreated base stocks were used to conduct necessary product development prior to introducing the new lubricant facility. Laboratory and engine dynamometer tests indicated that lubricating oils using hydrotreated base stock had superior control of diesel piston deposits and oxidative viscosity increase. Excellent performance of multigrade diesel engine oils using both hydrotreated and solvent-refined base stock over extended oil change intervals was demonstrated in extensive field trials. Cold weather benefits for multigrade diesel engine oils were defined by cold room studies and outdoor trials. Low volatility, high thermal stability, and good additive response were particular features contributing to overall performance improvements. Finished lubricants formulated from hydrotreated base stocks of similar viscosity index appeared to have similar performance characteristics, regardless of crude source.