Degradation and chemical change of longlife oils following intensive use in automobile engines

The paper researches the features and quality of longlife oils after the point of being recommended for replacement by the onboard computer. The longlife oils have their service life prolonged to 30 up to 50 thousand kilometres which is being monitored and evaluated by the onboard computer. The onboard computer then, on the basis of several parameters, modifies the interval to optimum value. Kinematic viscosity, TBN, the amount of soot, oxidizing and sulphating products, water, fuel, glycol and high antioxidant presence were measured. The results we obtained from the measurements do not correspond with the conclusions of onboard computers. (C) 2014 Elsevier Ltd. All rights reserved.