Lacquer-forming properties of motor oil under high-temperature conditions

Conclusions

• 1. A new method has been developed for assessing the lacquer-forming properties of motor oils with dynamic thin-layer oxidation at high (250–370°C) temperatures. The method makes it possible to:

• a) clearly differentiate base oils;

• b) assess the effectiveness of additives;

• c) select the optimal additive concentration for combined use;

• d) assess the compatiability of additives in the case of joint use.

• 2. Tests on oils and additives in the Sliding Ring device have established the following.

• a) Different additives display different patterns of behavior in the same base oil. With increasing concentration of the additive in the oil, the lacquer-forming capacity of the later may:

• 1) decrease;

• 2) increase;

• 3) first decrease, then increase;

• o 4) first increase, then decrease.

• b) Depending on the quality of the base oil, the effectiveness of the same oil in it may vary by a factor of 2–3.