Oil Temperature gauges ensure that your engine's oil temperature is flowing at correct temperatures, allowing for the correct method of lubricant warmup and cooldown. This will keep your transmission working much longer and let you know when it is time for maintenance. Running at a higher temperature than is needed is one of the most vicious enemies which war against diesel engines.
More on Oil Temperature Gauges - Diesel Trucks & More
The top piston ring exposes your oil to temperatures which can exceed 600 degrees Fahrenheit! Oil Temp Gauges are an important way to ensure that your vehicle has a long life and continues to run the way you depend on.