Aircraft engines rely on their oil systems for various functions, so it is critical that operators can always control and monitor the pressure within such systems. To achieve this, oil pressure gauges offer pilots readings of the aircraft oil system in pounds per square inch (psi) and indicate whether the system is in a safe operating pressure range. Pilots should consistently monitor the dial of the pressure gauge, that of which often indicates safe pressure zones when the dial is within a green zone. If pressure exceeds or falls short of the ideal operating pressure, the dial enters a red zone. Dangers of improper pressure within an oil system can interfere with many vital functions of the engine, such as the lubrication of its moving parts, the temperature of the engine as a whole, and the ability to remove contaminants from the system. Therefore, a pilot should be aware of the pressure in aircraft oil systems at all times and understand how to operate an oil pressure gauge. This blog will explore the functions of oil pressure gauges, and the important roles they play in maintaining the engine(s), oil system, and safety, in general.