The Impact of Diesel Engine Lubricants on Deposit Formation in Diesel Particulate Filters

Emission legislation for diesel engines is becoming more stringent over time. While the exhaust gas composition requirements for prior iterations of emission legislation could be met with improvements in the engine's combustion process, the next issue of emission limits may require more rigorous measures. In order to meet severe particulate matter limitations, such as those mandated in Japan's new long-term (2005-) emission regulation and in Euro-4 emission legislation, the use of exhaust gas after-treatment systems seems unavoidable. Many engine builders seem to have selected the Diesel Particulate Filter (DPF) as an integral part of their selected after-treatment strategy. It has been stated that engine lubricants may hurt the durability of such after-treatment systems when oil consumption results in deposit build-up on the DPF walls. This paper describes how a study was performed on the possible impact of engine lubricant composition on DPF plugging.