Soot and other insolubles are a mixture of combustion residues and oxidation products. Soot consists mainly of the following combustion residues: ash, carbon and partially oxidized fuel, a small amount of oil oxidation products and spent lubricant additive.

Soot in engine oil is:

• Carbon from incomplete combustion and to a small extent from lubricants

• Organic polymers from the oxidation of lubricants or fuels

• sulphates, from the combustion of sulfur from the fuel and from the reaction with BN additives

• Asphaltenes (predominant in engines running heavy oil) - a very dirty crankcase is known as "black paint" and is associated with asphaltenes in the oil

High levels of soot and other insolubles cause:

• Increased oil viscosity
• Bearing and tread wear
• Clogging of oil lines and filters

• Contamination in the area of ​​the piston rings, piston ring grooves and the piston crown

Testing equipment for carbon black and other insolubles:

Electronic Insolubles Test Meter - A stand-alone test device with modern measurement technology that provides fast results with very good repeatability.

Insolubles Test Papers - Test strips that provide qualitative results by comparison with comparison charts.