Evaluation of Oil Performance Using the TU High Temperature Engine Test with a View to Extending Oil Drain Intervals

The extension of engine oil drain intervals leads vehicle manufacturers to demand ever greater oil oxydation stability.

These demands are evaluated by various tests, and particularly with the help of the ASTM III E and the CEC TU3 High Temperature engine test, which allow:

• the evolution of the viscosity during test to be observed
• the aptitude of the oil to avoid ring sticking to evaluated
• the merit rating of piston cleanliness to established (absence of deposits)

This article aims to establish a correlation between the degradation of the engine oil in vehicle endurance and during theCEC TU3 High Temperature engine test on the test bench, and in high temperature laboratory tests. The results obtained on three types of oil (mineral, semi-synthetic and synthetic) while extending the oil drain intervals to 20 or 30000 km. As well as the oil thickening, the evolution of piston cleanliness during the vehicle endurance runs will be presented.

The results of tests on the new TU5JP engine (engine of 1585 cc instead of 1360 cc) will also be presented, and which confirm the interest of using it in place of the TU3 for oil qualification tests.