Determination of Total Acidic Number of Motor Oils of Diesels and Cars and Its Correlation to the Mileage

Oils are a major group of lubricants which are used to reduce the amount of friction and easier movement of two in contact surfaces that are extracted from crude oil. One of the most important applications of lubricants is the engine oil of vehicles. In this research, the Total Acidic Number (TAN) of various types of motor, gearbox, hydraulic, and brake oils were measured in different mileages. The oils were selected both for cars and diesel vehicles from a range of manufacturers. The results showed that the average TAN is 1.4 and 1.7 (mg KOH)/g for car and diesel motor oils, respectively. Also for most of the oils, there is a direct relationship between TAN and the mileage of the car. As for an average of each 5,000 km, TAN increases 0.7 (mg KOH)/g for car oils and 0.3 (mg KOH)/g  for diesel oil vehicles. Moreover, it was found that the TAN of brake oil is zero and do not change with mileage. Besides, TAN of the oil taken from the engine and from the inside of the oil filter is the same.