Development of an Automatic Engine Oil-Change Indicator System

To insure maximum engine life, it is essential that engine oil be changed as required. Some drivers are not aware that the oil should be changed, and others do not know how often to change it. To assist the driver in this regard, an automatic oil-change indicator was developed.

In developing the oil-change indicator, it was found that oil temperature, vehicle mileage, engine revolutions, and changes in the physical and chemical properties of the oil during use all provided an indication of oil degradation. Based on these measurements, a mathematical model was developed which relates oil life to oil temperature and either vehicle mileage or engine revolutions. Computer hardware and software suitable for use in a vehicle were developed based on the mathematical model. Vehicle testing, in conjunction with oil analyses, has confirmed the validity of the automatic oil-change indicator system.