Development of an Environmentally Friendly Two-Stroke Engine Oil for Power Equipment

Two-stroke engines have been normally used for power equipment such as bush cutters and lawn mowers because of their compactness and cost-performance. However, their exhaust smoke is often put in question for causing a poor working environment. Therefore, it is important to develop an environmentally friendly two-stroke engine oil. In this paper, the development of a two-stroke engine oil with low smoke performance and its evaluation results are reported.

If dilution ratio of a two-stroke engine oil with gasoline is increased in order to reduce the exhaust smoke, the lubricity becomes poor because of the decrease of base oil ratio in the oil. A two-stroke engine oil that copes with both low exhaust smoke and anti-seizure performance for pistons, has been developed by using a carefully selected polymer ester. The oil showed excellent anti-seizure performance in actual engine tests. In addition, it was also confirmed that it had better low smoke performance than commercially available engine oils using an exhaust smoke test with an actual bush cutter.