Oil viscosity

Here is very interesting video about "oil viscosity"

It says about oil viscosity and SAE.

in this video you can comparing between 5W-30, 10W-30, 15W-40, 20W-50 and 30

Viscosity
Viscosity is graded by measuring the time it takes for a standard amount of oil to flow through a standard orifice, at standard temperatures.
The longer it takes, the higher the viscosity and thus higher SAE code.

Paraffin wax
Paraffin wax refers to a white or colorless soft solid that is used as a lubricant and for other applications.