Trends in Engine Technology for Heavy Duty Commercial Vehicles and Requirements for Engine Oils

摘要

Heavy-duty commercial vehicles that are used as means of transportation and trucks playing a role in goods distribution are equipped mainly with diesel engines. Among internal combustion engines, diesel engines are distinguished by high durability, favorable fuel economy (energy and resource savings), and lower content of CO2{sub}, which causes the greenhouse effect, in exhaust gas. Therefore, it can be suggested that in the future the use of diesel engines will continue. On the other hand, in recent years, in many countries stricter regulations on exhaust gas emission from diesel engines have been introduced to prevent environmental pollution, which is of public concern. In Japan, such regulations were first introduced in 1974 and a sequence of regulations is planned to follow: regulations at the regional government level in 2001, new short-term regulations in 2003 and new long-term regulations in 2005. In addition, the demand for a longer lifetime of engine oils has grown more urgent for various reasons, including reduction of industrial waste. In the present work, problems related to future diesel engine oils will be discussed, bearing in mind the above requirements.