ABSTRACT
The large number of natural lubricating and specialty oils sold today are produced by blending a small number of lubricating oil base stocks and additives. The lube oil base stocks are prepared from selected crude oils by distillation and special processing to meet the desired qualifications. The additives are chemicals used to give the base stocks desirable characteristics that they lack or to enhance and improve existing properties. The properties considered important are
1. Viscosity 2. Viscosity change with temperature (viscosity index, or VI) 3. Pour point 4. Oxidation resistance 5. Flash point 6. Boiling temperature 7. Acidity (neutralization number)
Viscosity.
