What are the capabilities expected from an engine lubricant?

Anti-rust properties

Anti-corrosive properties

Anti-foam properties

Capacity to withstand the action of water which can affect additives or Resistance to hydrolysis

Anti-wear or capacity to contain wear 

Capacity to reduce surface friction of the lubricated parts or friction modifier

Thermal strength or capacity to withstand temperature changes

Capacity to the cold parts of an engine clean or Dispersivity 

Capacity to preserve oil film even in the presence of high pressures or Anti-scuffing

Capacity to resist the action of oxygen or Anti-oxidant

Capacity to separate contaminants or Demulsibility

Capacity to keep hot parts of an engine clean or Detergency

Capacity to stabilize the optimum viscosity or high viscosity index 

Capacity to neutralize acids formed during combustion or other sources thereby preventing corrosive wear or Alkalinity reserve

Capacity to separate insoluble elements or Centrifugibility and filterability