FRICTION MODIFIER

A substance which enhances the ability of oil to remain slippery. In most SH and SJ series oil, friction modifiers have been added to improve engine starting and prolong engine life. However, in engines with a wet clutch (i.e., the engine oil lubricates the clutch plates) such as motorcycle engines, oils with friction modifiers can cause the clutch to slip and may force the premature replacement of the clutch plates.