In this category you will find all the oils for your YAMAHA 4 stroke engine. How to select a good grade of oil for your 4 stroke engine in all seasons? It is very simple! First of all there is the first cold grade (before the W which often goes from 0 to 25) which the lower it is, the more fluid the oil is at negative temperatures and therefore protects your engine when cold. And then the number after the W, the hot grade, often from 20 to 60, the higher it is, the more viscous the oil is and the more it protects your engine at high temperatures. It should be noted that an optimal engine runs between 80 and 90° and risks overheating from 110°!