Road tests of oil condition sensor and sensing technique

A new oil condition sensor was designed and fabricated. The newly designed sensors were installed in three vehicles and tested on the road. The test results indicated that the degradation of engine oil could be divided into three stages: (1) good, (2) rapid increase of total acid number (TAN), and (3) rapid increase of viscosity. The onset of the second and the third degradation stages could be detected by analyzing the trend of sensor outputs. The performance of the sensor was verified by analyzing the oil samples periodically collected from the road tests. The oil condition sensor could also detect water condensation and antifreeze contamination in engine oil.