5w30 vs 5w40: Which is the Best| Difference between 5w30 and 5w40

Last updated on January 13th, 2023 at 07:30 pm

​Are you confused about 5w30 vs 5w40, and don’t know which is the best oil for your car? Have you ever come to ask yourself this question “can i use 5w40 instead of 5w30”?

Well. In today’s article, we will share with you the main difference between 5w30 and 5w40, that way; you can decide which one to get when buying oil for your car. Related article: What Happens If I Use 5w30 Instead Of 5w40

5w30 vs 5w40: Which is the Best| Difference between 5w30 and 5w40

Anytime it comes to renewing car oil, many car owners just drop off their car with their mechanic hoping they know which oil is best for their car. While others, the car manufacturer’s manual isn’t the final say when it comes to the type of oil that is good for their car.

Note that whether you like it or not, changing your car’s oil is strictly your responsibility. Meaning that you ought to know what oil is best for your engine since it would lead to an optimal engine performance.

But note that the 5W30 and 5w40 are both motor oils, so we shall be discussing which of these oil is best for your car.

However, before going into the difference between 5w30 and 5w40 oil, we most first consider the importance of choosing the right oil for your car.

Importance of Choosing the Right Oil

​You should know that choosing the right motor oil will help prolong the engine lifespan of your car.

And this is because motor oil help to lubricate the engine parts so that they do not grind against each other which leads to wear and tear.

This means using the wrong oil will cause your engine parts to be replaced in a short period.

Making sure that your engine perform well isn’t just about choosing the right oil, it also requires you changing oil every 3000 to 5000 miles to preserve the engine condition.

Indeed, a regular oil change is essential and helps you to avoid having dirty oil which isn’t effective in lubrication and cooling.

If you don’t change your oil, you can render your warranty invalid and disqualify your car from any repairs or maintenance.

5w30 vs 5w40 high mileage or 5w30 vs 5w40 oil for a Low mileage

When thinking which of then 5w30 vs 5w40 oil to go for high or low mileage vehicle there are factors you should consider.

Such as the viscosity of each oil and here below is what you need to bear in mind.

Factor to Consider When Choosing Your Motor oil

  • ​Oil Viscosity

​Please not that viscosity is the ease at which liquid flow. And the viscosity and thickness of oil are closely related.

Note that the thicker your motor oil, the more viscous it is. But on the other hand, a thinner oil has a lower viscosity.

The 5w30 and 5w40 motor oils have the number 5 which is then followed by W, which represents “winter”.

This simply means that both 5W30 and 5W40 motor oils have the same viscosity in winter, which is 5 and moderately low.

It also indicates that the oils flow at very low temperatures but easier through the engine. 

However, this is a good quality of motor oil because every viscous motor oil such as a 20w, will not flow easily via low temperatures.

Meaning that it will make the oil unable to distribute via the engine when it is cold thereby leading to damage and wearing away of the engine. 5w30 Vs 5w40 Which Is Thicker?

How Weather Affects Type of Motor Oil

It is true that climate and weather plays a major role in determining the type of motor oil that we use for our vehicles. A lower temperature will demand a lower viscosity. 

And the oil flows easily via the system ensuring that the engine is at peak performance and this is why both the 5W30 and 5W40 are proper for colder temperatures unlike the 10w or 20w oils.

You should be aware that high temperatures requires a slightly higher viscosity, but shouldn’t be too high to affect effective flow. This is because you do not want oil that is too thin and easily flowing as it could have long term negative effects on your car.

This means that if you want to choose between 5w40 vs 5w30 oil that is not too thin such that will flow easily thereby affecting your car negatively, which should it be, 5w30 vs 5w40?

  • ​5w30 Engine Oil

5w30 engine oil is the most common engine oil in the market. It is the type of motor oil that can be used for different kind of vehicles which works effectively for a wide range of temperatures.

And because of its versatility, its very popular among car owners, but it is more preferred for winter periods even though it can also be used in warmer summers.

  • ​5w40 Engine Oil

This 5w40 engine oil is not as popular because it’s not commonly used as the 5W30, but using the oil helps to promote your engine health. 5w40 oil helps to protect the engine from buildup and sludge, which helps to prevent damage.

​So 5w30 vs 5w40, which is better?

​Although these two important engine oils (5W30 and 5W40) are mostly similar in some ways.

Also, they are very effective and functions better during colder periods thus efficiently lubricating your engine.

Meaning that the oil moves properly through all the parts hence making it very easy to rev the engine in cold weather.

And also, they are both used for warmer temperatures because of their thickness which provides necessary protection for the engine.

One of the main difference between the 5w30 and 5w40 oil is the viscosity of both oils in warmer temperatures. ​

As the 5w30 is more suitable for colder temperatures while the 5w40 is much better for warmer temperatures.

So what’s the difference between 5w30 and 5w40

The main difference between 5w40 vs 5w30 in this post are discussed based on the following factors which are:

  • Lower Viscosity rate
  • High Viscosity rate
  • Temperature range
  • Fuel Economy
  • Oil Flow  5w40 and 5w30
  • Application  5w40 vs 5w30
  • And  Thickness of 5w30 and 5w40

The difference between 5w30 and 5w40

  • A Low-Shear-Rate Viscosity for 5w40 and 5w30

Be aware that the viscosity of 5W40 is from 12.5 to 16.3 mm2/s at 100g, while the viscosity of 5W30 is from 9.3 to 12.5 mm2/s at 100g.

But both of these motor oils are 5 grade when cold, and however, 5w30 oil is 30 grade, and 5w40 oil is 40 grade at operating temperatures.

The 5w40 oil has a higher viscosity than 5w30 with higher temperatures in summer, which adds to proper performance of the car.

  • Temperature range for 5w30 and 5w40

The 5w30 is used in temperature which ranges from -25°C to 25°C, while the 5w40 is used in temperature ranging from -25°C to 35°C.

  • High-Shear Rate Viscosity

Note that a working viscosity of 5W40, the high-shear rate is min 3.5 at 150g, while for working viscosity of 5W30, the high-shear rate is at least 2.9 at 150g. It simply gives you an idea of ​​how much the oil withstands in extreme loads.

  • Fuel economy

The 5w40 has a poor fuel economy compared to the 5W30.

  • Oil flow

The 5w40 provides higher pressure than the 5W30, but with less flow.

  • Application

The 5w30 oil can be used by different vehicles in different range of temperatures. But this is ideal for colder temperatures.

While the 5w40 is often used in higher mileage engine sand and functions better in warmer temperatures.

  • Thickness of 5w30 and 5w40

The 5W30 is lighter than 5W40, which makes it to have a better fuel consumption.

The cost: Which is more expensive?

The 5w30 is more costly than 5W40.

Conclusion on 5w30 vs 5w40 oil  

To choose the right engine oil that is perfect for your car shouldn’t be a problem.

But before you decide between these two motor oils, you need to know which oil your car manufacturer recommends.

A lot of car owners opt for the 5w30 engine oil due to its versatility. This is because 5W30 motor oil has the ability to withstand a high range of temperature, and can be found in the market easily when compared to the 5W40 motor oil.

But when looking at 5w30 and 5w40 for your vehicle, it should be dependent on what your car manufacturer recommends.

So make effort to stick to that except on rear cases where you are not able to that specific one but temporarily sort for another type.

I hope this post showing you what is the difference between 5w30 and 5w40, is helpful to you?

Be sure to share and bookmark this post for feature reference.

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