Motor Oil Info

Viscosity is the measure of the internal friction of a fluid. The greater the friction, the greater the amount of force required to cause this movement, which is called “shear.” Shearing occurs whenever the fluid is physically moved or distributed, as in pouring, spreading, spraying, mixing, etc. Highly viscous fluids, therefore, require more force to move than less viscous materials.

Viscosity Index is defined as: The relationship of viscosity to temperature of a fluid.

High viscosity index fluids tend to display less change in viscosity with temperature than low viscosity index fluids. So generally speaking, oils with a viscosity index of better than 120, are the most stable, or least susceptible to change with temperature. The oils with a viscosity index below 120 are the most unstable or most susceptible to change with temperature. AMSOILs use of PAOs gives our products some of the highest viscosity index numbers possible. This translates to our products being very stable under extreme temperature changes, i.e. gas or diesel engines.

AMSOIL Diesel Oil has a high viscosity index.