TBN levels are targeted for the intended application. For example, gasoline engine oils typically display lower TBN numbers while oils in a diesel engine must manage high contaminant-loading from soot and sulfur and typically run higher.
TBN levels decrease as the oil remains in service. When the level reaches a point where it can no longer protect against corrosion, the oil must be changed.
Oils that are formulated specifically for extended drain levels typically display elevated TBM numbers to ensure proper corrosion protection for the duration of the extended interval.
Amsoil Advantage
Because AMSOIL lubricants contain consistently high TBNs, they neutralize acidic contaminants formed during the combustion process and keep these contaminants in suspension to prevent corrosion.
Amsoil lubricants use detergent and dispersant additives to significantly reduce sludge and carbon deposit formation better than conventional oils.