Electrical techniques for monitoring the condition of lubrication oil

The lubricating oil used in engines for vehicle and other applications is renewed according to a schedule specified by the manufacturer. This timetable is, naturally, very conservative, and makes no allowance for the way in which the engine is operated. Constant-speed operation (such as motorway use) is much less harmful to the lubricant than variable-speed operation, such as urban driving, during which the oil experiences extreme variations of temperature and engine speed. The net result of the conservative lubricant replacement schedule is that most engine oil is discarded well before it has reached the end of its useful life.