The first oils certified for use in exhaust-gas-recirculation (EGR)-equipped diesels will be available in June 2002, according to the American Society for Testing and Materials’ Heavy-Duty Engine Oil Classification Panel. Jim McGeehan, manager, engine oil technology, Chevron Products, Richmond, Calif., chairs the panel.
In order to meet the Environmental Protection Agency’s exhaust emissions requirements for October 2002, most, if not all, light, medium and heavy-duty diesel engines will use cooled EGR. That’s because recirculating a small amount of exhaust gas into an engine’s intake stream lowers peak cylinder temperatures, which lowers oxides of nitrogen (NOx) in the exhaust.
Because lower peak cylinder temperatures mean somewhat less efficient combustion, EGR will increase acid and soot levels in engines. And, since soot (or particulate-matter) levels must remain unchanged for 2002, much of the soot will need to be absorbed by engine oil, rather than being expelled at the exhaust pipe.
Consequently, to prevent acid and soot-induced engine damage, a new oil category is being developed, called, for now, Proposed Category 9, although the commercially available product is most likely to be designated API (American Petroleum Institute) CJ-4.
The new oil category is being driven by three new engine tests – operating with 15 percent EGR – which address ring, liner, bearing and valvetrain wear, piston deposits, oil consumption, filter plugging and sludge formation.
In all, there are seven fired-engine tests and six bench tests covering all the engine oil parameters in the category.
Oil performance for the final product will be achieved by varying base stocks and additive packages until the test goals are met.
