Development of Future Low Emission Engine Oils 2003-01-1990
Since the 1970's, governmental organisations in Europe, USA and Japan have started to set exhaust gas emission limits on new vehicles. The regulation of emissions has now spread to South America, Australia, India and much of the Far East. Governmental agencies are primarily concerned with environmental effects of engine emissions. Regulated emissions limit the amount of carbon monoxide, hydrocarbons, oxides of nitrogen and particulates in the exhaust stream. These limits have been regularly reduced and future reductions have already been set as far ahead as 2010.
In order to meet these limits, engine manufacturers are continually redesigning their engines. For heavy duty diesel (HDD) applications this has primarily meant improvements in combustion through turbo charging, intercooling and higher fuel injection pressures and in some cases the use of exhaust gas recirculation (EGR). To meet the future emission level limits in Japan, Europe and the USA, OEMs have indicated their intention to use exhaust after treatment devices to further reduce pollutant levels.
All these changes to engine technology have demanded changes in lubricant technology. This has generally meant significant formulation changes incorporating more highly refined basestocks and the use of novel additive technology.
This paper outlines the major changes in HDD emission limits, the corresponding changes in engine technology to meet those limits and their effects on lubricant technology. It shows that lubricant development to meet these requirements is well underway, but there are still significant challenges and unknowns to be faced before such oils are fully developed.