Engine Oil (aka Motor Oil or Finished Oil) have eleven different viscosity grades:
The Society of Automotive Engineers (SAE) developed a scale for both engine (motor oil grades) and transmission oils. These numbers are referred to as the weight of a motor oil.
Engine oils are blends of refined mineral oils with high performance additives. They are recommended for use in a wide range of applications including gasoline and light duty diesel engines found in passenger cars, agriculture, construction and certain hydraulic systems.