5w40 vs 10w30

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You will come across many brands of motor oils in the market. And, to choose one among them is a tedious job. Not only confusing, but also it’s scary when you think of using inappropriate oil in your vehicle.

A wrong oil can damage the internal components of the engine and can lead to a hefty loss. But, to make your task easy, we can suggest two oils, 5w40 and 10w30, that are ideal options with optimal viscosity. However, they do have specific differences, too, so let’s check them out.

5w40 vs 10w30

The vehicles compatible with these engine oils are many, but the owners are often confused about choosing the right oil. Therefore, they seek to know the perks and differences between the oils to decide what is good for their vehicle.

And this 5w40 vs 10w30 article intends to help them with this search. So, follow this article to know these oils and their differences and similarities to make a better decision.

5w40 Specifications

The selling point of the 5w40 engine oil is its reliability of performance. The best part is that 5w40 performs optimally when under pressure.

And the sole reason for this high-end output is that it is a synthetic blend oil. It intends to offer protection to the engine against contamination, thereby acting as an ultra-shield.

A car engine of an orange toned car

In addition, this oil comes with the potential to work in frigid temperatures, with a fast initial start-up. Along with that, it also consists of a built-in cleaner agent to keep the components free from dirt and rust.

Hence, the overall life of your vehicle engine multiplies exponentially. Furthermore, thermal stability is yet another potent feature of this oil that plays a major role in resisting the oil aging attributes.

Furthermore, this oil doesn’t emit many harmful components. And, this makes it safe for the environment as well. All of the features are evident reasons for which the demand for this oil is inevitable.

Moreover, the manufacturers are putting their immense effort to maintain a constant pace in producing this oil of multi-grade composition.

The numbers over the oil name 5w40 denote its viscosity level at low and high temperatures. The number 5 signifies the low-temperature viscosity of this oil, whereas the number 10 gives us an idea about the high or operating temperature viscosity.

It concludes that this oil is ideal for both cold and hot regions, without any doubt. Moreover, it is preferable for all modern engines that showcase high performance.

10w40 Specifications

When you own an automotive vehicle, you need to take concern for its gear, engine, and clutch. These components are the life of a vehicle, and you need to feed them with ideal lubrication.

Keeping this in mind, 10w30 is an ideal engine oil worth the price and offers that extra mileage you crave. Furthermore, 10w40 serves modern applications and has optimal viscosity to determine the seamless flow within the engine components.

It is a full-synthetic formula that intends to offer you ideal lubrication and enhance the life of your vehicle engine. One of the major strong zones of this oil is its thermal stability potential.

Automotive cyliners of a car engine

It is a stiff oil that offers the best-in-class service for a long time until it demands replacement. Also, the friction properties within this oil are the reasons for its complete efficiency.

Irrespective of the weather or temperature, 10w30 engine oil works seamlessly and at a constant pace. The numbers within this oil type, 10w30, denotes the viscosity rating as specified by SAE.

The number 10 denotes the viscosity of this oil at low temperatures, whereas the number 30 denotes the viscosity at operating or high temperatures. In either case, this oil is crucial to give you adequate lubrication in both winters and summers.

The repetitive motion of the cylinders within the block leads to wear & tear of the engine. However, with ideal lubrication of 10w30, it can be controlled, and this, in turn, can reduce the contact between the block and cylinder.

Hence, the life of the engine will increase. It is an expensive oil, but it lasts for a long time before it demands replacement.

Similarities of 5w40 and 10w30

  • Both of these oils have thermal stability, which is their strong zone.
  • They both are preferable for modern engines.
  • Both 5w40 and 10w30 are ideal for both cold and warm regions.

Differences of 5w40 and 10w30

  • 5w40 consists of an advanced synthetic lubricant, whereas 10w30 is a full-synthetic formula.
  • The sulfated ash within 5w40 is at 1.3%, whereas for 10w30, it is 0.8%.
  • The viscosity of 5w40 at 100 degrees Celsius is 13.7, whereas, for 10w30, it is 10.7.
  • 5w40 is suitable for SUVs, Passenger cars, Light Trucks, and other modern vehicles. 10w30 is suitable for modern SUVs, high-performance vehicles, and even truck engines.

Major Distinguishing Factor

The major distinguishing factor between 5w40 and 10w30 lies in their viscosity index. The higher the index, the better is the performance!

For example, the viscosity index of 5w40 engine oil is 176, whereas the viscosity index of 10w30 is 146. With this, we could recognize a pattern and apply this to other engine oils such as 10w40.

An engine of a Ferrari car

When to Use 5w40?

5w40 is an expensive oil, and you must prefer it exclusively for the winter climates. Even though this oil is preferable for all seasons or temperatures, the low viscosity rating of 5 is what makes it more apt to be used in cold temperatures. 

When to Use 10w30?

10w30 is an ideal pick for heavy truck engines and modern-day SUVs, making it a robust oil. However, just like 5w40, this oil is also suitable for all seasons and climates.

Still, 10w30 is more proficient for summer or hot temperatures due to its low high-end temperature viscosity. When considering other machines, such as lawnmowers and generators, SAE30 should also work when paired with 10w30.

Final Verdict

It would be best to keep in mind that the first thing you should do while choosing the oils is to refer to the manufacturer’s manual, be it a synthetic oil or a regular oil.

If it permits you to use 5w40 or 10w30 oil in your vehicle, then you can make your choice between them. To know even more about 10w30, there is also a comparison between 10w30 and 5w30, which is relatively closer to 5w40.

In addition, knowing the differences and specifications about cost, viscosity, thickness, and others can help you make a better decision.