ENGINE OIL DEGRADATION ESTIMATING DEVICE AND ENGINE OIL OXIDATION PREVENTIVE PERFORMANCE ESTIMATING DEVICE

摘要

To provide an engine oil degradation-estimating device and a device for estimating antioxidant performance of engine oil which are capable of determining degradation and an antioxidant performance of engine oil inexpensively and accurately, thereby making it possible to properly determine degradation of the engine oil and the time for replacement of the engine oil. The engine oil degradation-estimating device includes an ECU 2. The ECU 2 estimates an antioxidant performance OIT and a cleanliness preservation performance TBN of engine oil, and determines degradation of engine oil based on the estimated antioxidant performance OIT and cleanliness preservation performance TBN. The device for estimating antioxidant performance of engine oil also includes an ECU 2. The ECU 2 acquires concentration [FUEL] of fuel in engine oil, and estimates the antioxidant performance of the engine oil based on the acquired fuel concentration [FUEL].