Motorcycle engine oil for four-stroke engines one liter with a viscosity grade of 5W-40.

Engine lubricants have two main functions: the first is to reduce friction between moving parts, while the second is to dissipate heat from the engine walls.
The viscosity numbers indicate how thick a lubricant is. It is represented by 2 numbers: the first with the letter "W" (Winter) refers to how the oil flows when it is cold, while the second refers to how the oil flows when it is hot under engine operating conditions.
The selection of a lubricant as well as when to change the lubricant in the engine should be done with care and always according to the information provided by the manufacturer in the user manual.