Can Thick Motor Oil Cause Low Oil Pressure?

Understanding the functioning of an engine is crucial for ensuring its longevity and performance. Many factors can affect the oil pressure in an engine, and the thickness of the motor oil is one such factor. While it is a common belief that using thicker oil increases oil pressure, the relationship between oil thickness and engine oil pressure is more complex than it might seem. In this article, we will explore the factors that influence oil pressure, the role of oil viscosity, and the potential consequences of using the wrong oil thickness.

How Does an Engine Work?

To truly understand the relationship between motor oil thickness and oil pressure, it is essential to revisit the basic mechanics of an engine. As Richard Neal and Richard Widman pointed out, the oil pump does not create oil pressure by itself. Instead, it is the clearances between the engine parts that generate the necessary pressure. As engine parts wear over time, these clearances increase, leading to a decrease in oil pressure.

The Role of Oil Viscosity

Viscosity, or the thickness of the motor oil, is a critical factor in determining the oil pressure. Thicker oils provide higher resistance to flow, which can help in maintaining pressure, but they can also have drawbacks. Adding thicker oil can give a slight boost in pressure, but this effect is usually minimal and varies depending on the degree of wear in the engine and the specific design of the oil pump.

Lower Viscosity and Its Effects

Lower viscosity oil flows more easily, which can reduce the pressure in the oil line. This phenomenon can be attributed to several factors, including aeration and the ability of the oil to flow through the engine components. When oil becomes too thin, it can bypass the gears in the oil pump, resulting in less oil being pushed out to the bearings and a subsequent drop in pressure. Additionally, too thin oil can cause it to flow out of the bearings too quickly, further reducing the pressure.

The Impact on Engine Performance

The impact ofWrong oil viscosity is not limited to a drop in oil pressure; it can also lead to increased wear and damage to engine components. Lower viscosity oil is more prone to aerating, meaning it can form air pockets in the oil pump. This aeration can be detrimental as air is not as effective a lubricant as oil, leading to increased wear and even damage to the oil pump itself.

Engine Clearance and Viscosity

Engine oil pressure is crucial for ensuring proper lubrication and maintaining the integrity of engine components. The specific design of the engine, including clearances between moving parts, plays a vital role in determining the optimal viscosity of the motor oil. Engineers design engine lubrication systems and oil clearances around specific viscosity ranges to ensure that the oil provides adequate lubrication without compromising the oil pressure.

Conclusion

While using thicker motor oil may seem like a simple solution to increasing oil pressure, the reality is more complex. The relationship between oil thickness and pressure is influenced by various factors, including engine wear, oil viscosity, and the design of the oil pump and engine clearances. It is essential to follow the manufacturer's recommendations for oil viscosity to ensure the best performance and longevity of your engine.

Key Points Summary

Thicker motor oil can provide a slight boost in oil pressure but can also increase wear and damage to the engine. Lower viscosity oil flows more easily and can aerate, leading to lower pressure and potential damage. Engine wear and clearances play a significant role in determining the optimal oil viscosity. Using the recommended oil viscosity is crucial for maintaining the integrity and performance of the engine.

For more information on engine maintenance and lubrication, consult the manufacturer's guidelines or a professional automotive mechanic.