What is a Motor Meter?

A motor meter is a device used to monitor an engine's running time. This is important to monitor proper oil change and maintenance intervals. There are different types of motor meter designs all made to monitor specific processes. Some designs monitor and track actual engine run time, while others record engine speed in revolutions per minute or RPM. Most motor meter's are wired into an engine's electronic or ignition system and are not easily disconnected.

The typical use for a motor meter is to monitor diesel engine run time. This is done due to the tendency of diesel engines to spend a great deal of time idling. The diesel engine is difficult to start in cold weather climates and, as such, it is left idling in the cold weather. The typical motor meter will keep track of the total time the engine has been operational and not simply actual driving time. This creates a much more accurate method of tracking engine function and run time.

In many instances, the motor meter will be compared to the vehicle's odometer or to a hub meter. The hub meter is mounted to a vehicle's wheel and monitors the actual driving time a vehicle spends on the road. By comparing the hub meter to the motor meter, a mechanic can decipher the difference in driving time as compared to idling time. This feature also shows the driver's actual driving time versus resting or sitting time.

Most companies that operate vehicles with motor meters also provide a very stiff fine up to and including termination for any driver caught manipulating the meter. The cost of a modern diesel semi engine is staggering. Any attempt to alter information that might jeopardize maintenance is often seen as a reason for termination.

While the typical motor meter is a mechanical device that is operated off of an electrical system, there are more modern versions which run within the vehicle's computer system. This internal meter is wired into the vehicle's on-board computer and can only be accessed by downloading the information. This type of meter is much less prone to sabotage and manipulation by an operator. In many cases, the driver of the vehicle is unaware that the meter even exists. More sophisticated systems can be monitored on the fly by an on-board tracking system.

With the cost of maintaining and operating a fleet of semi trucks on the rise worldwide, the use of engine monitoring systems is increasing. The ability to avoid engine problems through good preventive maintenance is beneficial to the operation budget. This is another case of a low-cost unit being responsible for a much higher cost unit.