The condition of the motor oil in civilian cars is difficult to monitor; hence, we propose a method to evaluate the degree of degradation of motor oil using an on-board diagnostic (OBD) system. Three civilian cars and four motor oils (containing mineral oils and synthetic oils) were subjected to five groups of road tests under urban traffic and high-way conditions. The operation information, oil service time, mileage, engine operation time, idle time of the engine, and number of start-ups of the engine were obtained using the proposed OBD system. Physiochemical properties and changes in the components of motor oils during road tests were analyzed in laboratory. The theoretical model of the comprehensive indicators of driving parameters and oil properties were established. The proposed method was successfully applied to different cars, motor oils, and operating conditions in road tests. All the theoretical models had high accuracy and precision. Herein, we provide a method to monitor the oil condition with real-time driving parameters and provide a reference for end users to change their motor oil reasonably.

中文翻译：

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基于车载诊断系统的机油状态评估

民用车机油的状况很难监测；因此，我们提出了一种使用车载诊断（OBD）系统评估机油降解程度的方法。在城市交通和公路条件下，对三辆民用汽车和四种机油（包含矿物油和合成油）进行了五组路试。使用所提出的OBD系统获得了运行信息，机油使用时间，里程，发动机运行时间，发动机怠速时间以及发动机的启动次数。在实验室中分析了路试过程中机油的理化性质和成分的变化。建立了驱动参数和油性综合指标的理论模型。所提出的方法已成功应用于各种汽车，机油，和路试中的操作条件。所有的理论模型都具有较高的准确性和精度。在此，我们提供了一种通过实时驾驶参数监控机油状况的方法，并为最终用户合理地更换机油提供了参考。