Have several functions. The most important is the maintenance of engine details cleanness. As a rule, several types of detergents are used: sulfonates, sulfofenates and alkilsalitsilates. It is possible to use separate types of additives and combinations of additives. The principle of activity of these additives in engine is the same as detergent agents using in everyday life.
Besides, detergents possess alkaline characteristics, it means that they can neutralize acid. Acids are formed under sulphur burning that fuel contains, especially in diesel fuel and under oxidation of oil itself.
By neutralizing such acid products, preventing effectively engine corrosion. The second function of such additives is an acid and anti-corrosion neutralization.
It is a scope of neutralizing characteristics entering into engine oil. It is measured in mg KON/g. TBN can be changed in a wide range: from 5 mg KON/g (for gas engines, where the sulphur contents is near zero) to 100 mg KON/g (for marine engines, working on mazut with the sulphur contents more than 3,5%). Ordinary engine oils for automobile engines have TBN over the range of 5…20 mg KON/g. TBN doesn’t pointed out on labels of oil can. If it is necessary, oil producing companies can present TBN information to consumer.
It’ s very important to know that at real conditions TBN doesn’t have practical importance. The most important characteristic is the TBN falling speed (contamination of oil neutralizing possibilities). TBN changing relatively its basic meaning (ordinarily on 50% ) is one of the characteristics which are used by engineering producers for terms of substitution identification but not its absolute meaning. Speed of TBN falling is influenced by the type of used detergent. In the process of engine working the quantity of detergents is decreased.