What is Total Base Number (TBN)?
Total Base Number is a measure of the oil’s ability to fight acidity and corrosion, which stems from acid formation due to combustion of the diesel fuel. A significant proportion of these acids come from sulphur in the fuel which reacts during the combustion process and builds sulphuric acid, a very corrosive and acidic component. The TBN measures the level of the oil’s additive to fight acids. The initial of level of TBN can be one performance indicator, the depletion rate a very important second, which is mostly overlooked. Different additives can contribute to the fresh oil TBN number, however, these additives can vary significantly in their effectiveness in combating acid corrosion. Therefore, we should not only look at the initial TBN of the oil, but also at the TBN retention. It is possible for oils to continue to function extremely effectively even with low TBN levels, particularly when low sulphur fuel is being used.
