当中速筒形活塞发动机在七十年代中期发展并普遍使用重油时,不得不同时发展润滑油添加剂以克服相应的问题。那时的滑油试验机转而使用重油,其试验方法亦有所改变。然而,到八十年代,这些试验机已没有真正的代表性。因此,推出了一种更具代表性的发动机且通过试验确定了适当的试验条件。进一步的试验表明这种发动机给出的结果相同,而且对两种不同的滑油能清楚地区别。 When mid-speed cylindrical piston engines were developed and commonly used in the mid-1970s, they had to simultaneously develop lubricant additives to overcome the problems. At that time, the test machine turned to heavy oil, the test methods have also changed. However, by the eighties these testers had no real representation. Therefore, a more representative engine was introduced and the appropriate test conditions were determined through experiments. Further tests showed that this engine gave the same results and clearly distinguishes the two different oils.