Difference Between 5W30 and 5W40 Motor Oil

Engine oil plays an essential part in the car operating process, and manufacturers usually recommend occasionally services after some hours of using or mileage coverage.

Most drivers prefer to drive down to an automobile workshop when the time to replace the oil comes, but a few love to do it themselves. Doing it yourself can be adventurous and as rewarding as taking the car to an expert. You only need to understand the engine requirement to be able to determine the right oil for you. Information about the appropriate oil to use is usually contained in the user’s manual.

In this article, we shall be looking at two different engine oil grades, and you will be learning about their functions, when to use them, and their differences. The two oils are 5w30 and 5w40.

Difference Between 5w30 and 5w40 Oil

These digits represent the statistical code assigned to the respective oil by the Society of Automotive Engineers and indicate their viscosity. The viscosity of an oil is its thickness when felt with the hand. It can be as thick as that of honey and as the light of water. The higher the number, the higher the viscosity of that oil. 

The more viscous the oil is, the more resistant it is to flow, and the lower the thickness, the easier it will flow out when poured. The w in between the digits on the right and left stand for winter. The number on the left indicates the oil’s viscosity during winter, i.e., extremely low temperature. In contrast, the number on the right shows the oil viscosity when the temperature is high.

The viscosity of an engine oil changes with its temperature. This is due to the chemicals that were used to formulate it. Thus, the 5w40 engine oil is more viscous than the 5w30 at high temperature.

Why Knowing Oil Thickness Is Vital?

The thickness of the engine oil determines how effective it will be for the operation it is being used for. No doubt, the engine oil keeps all the movable parts of an engine going continuously without a breakdown of the machinery. 

The engine of a car could become permanently damaged due to a shortage of oil. The components keep moving against each other during operation, and friction is being generated. Low viscous oil will quickly get to all the hidden parts and keep them lubricated adequately than a high viscous oil.

For people who live in an environment where the temperature is colder, the appropriate oil to choose between the duo will be 5w30. However, refer to the top of your crankcase to see the exact grade of oil recommended by your engine manufacturer; that is your best option.

Note that no oil can work well in extreme weather conditions, dusty environments, rough driving, etc. at the same time. But, if you go for quality engine oil, your car engine will work better, and there won’t be a need for frequent changes as is required in ordinary oil brand. 5W oil is generally good for cold weather. Therefore, both 5w30 and 5w40 will do a good job. Having some at hand before winter, i.e., a great idea.

Single Grade vs. Multi-Grade oil

The thickness of oil reduces as temperature increases. As a car is moving, the temperature gets hotter, so the oil flows better and better. A multi-grade oil works differently and thus are suitable for both hot and cold weather. A multi-grade oil is formulated with compounds that make it viscosity thicker even as the temperature keeps increasing.

5W30 Motor Oil

This oil is one of the most commonly used oil used for car engines, and the reason for this is quite apparent. The first reason is that it works well with different car engines type, while the other reason is that it is ideal for use under a warm atmospheric condition. Therefore, regardless of the vehicle, it serves its purpose well. 

5W40 Motor Oil

This oil grade is not as common as the 5w30 grade, although it has some unique advantages that are worthy of mention.

Firstly, it protects the engine from the deposit of specks of dirt and sludge, which can lead to damage. This makes sure that the engine cranks quickly at startup and the oil flows smoothly during winter and other extreme cold weather conditions. 

5W30 vs. 5W40

When most drivers choose between 5w30 oil and a 5w40, the generally most preferred option is the 5w30. This is because on the oil pump. The 5w30 oil will have a smooth impact on the pump, making it more suitable when it gets heated. However, 5w40 is also a good alternative whenever the 5w30 is not available.

On the technical level,  the number 5 that is written before w on both oil grade shows that they have the same level of viscosity at low temperatures, but at high temperatures, the 5w30 has a lower density that the 5w40. 

Remember that the lower the thickness, the easier it is for the oil to reach vital components inside the engine. If you are in a situation where it is difficult for you to choose between the two oils, we recommend that you go for the 5w30.

This is because it works best for both cold and hot conditions. However, it is way more expensive than 5w40. If you can’t afford to go for it, then 5w40 will serve the same purpose without damaging the engine. 

Wrap Up

Servicing your car engine from time to time is going to help prolong the usability of the engine. Changing of engine oil is a vital aspect of servicing, and with the concepts that we have discussed, you will easily change your oil yourself without needing to visit an auto mechanic. 

Factors such as environmental temperature and the conditions of work help to determine the appropriate oil to use per time. However, do make such you refer to your car manual for better guidance.

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