ABSTRACT
Diesel engines have seen remarkable changes since the first designs introduced by Rudolf Diesel in the 1890s. As the diesel engine designs progressed, so did the lubricating oils used in these engines. This chapter focuses on engine oils used in heavy-duty off-road engines in terms of performance requirements, not the chemistry and formulation details, which require their own discussion. The details of diesel engine designs, theory, modeling, and simulation are of vast complexity and have been the targets of numerous references and elaborate courses. The complex processes, encompassing timing and design of fuel injection, piston movement with respect to the crank angle, intake air introduction, and exhaust gas evacuation, are the basis for the varying engine system designs. Four-stroke diesel engines are the most commonly used heavy-duty engine design. Turbocharging is another key feature of modern diesel engines and one that has direct impact on the oil life in these engines.
