5w30 vs 5w40: Determining Which Motor Oil Is Right For Your Car

People often get confused when it comes to picking the right motor oil for their car. They used to get trapped between the two main oils – 5w30 and 5w40. Both these motor oils come with different properties and specifications. So, to help you find the best one for your car, we’ve compared the two of them with more precision. Explore 5W30 vs 5W40:

The main purpose of motor oil is to protect your car by reducing friction and wear of the movable parts. A large variety of motor oils is available on the market. Out of which 5w30 and 5w40 are the most preferred choice of the people out here. Here are a few features of both these types of oils.

5w30 vs 5w40 – Which One is Better?

The main purpose of motor oil is to protect your car by reducing friction and wear of the movable parts. A large variety of motor oils is available on the market. Out of which 5w30 and 5w40 are the most preferred choice of the people out here. Here are a few features of both these types of oils.

Highlighting Features of 5w30

Know about 5w30 vs. 5w40
Learn about 5w30 vs. 5w40. (Photo: EngineLabs)

5w30 is a type of motor oil that helps to make your vehicle engine hum like a new one. Its main advantage is to protect and keep the engine parts in the best condition and operate smoothly. In addition to lubricating ability, some other well-known oils such as Amsoil 5w30 LS Synthetic European Motor Oil also save fuel for vehicles and clean effectively with high-grade additives in the formula. Besides, it helps in increasing the fuel economy of the vehicle. Some of the prominent features of this motor oil are:

  • Improves overall performance
  • Offers excellent wear protection
  • Lubricates the engine
  • Used for normal to extreme driving conditions
  • Suitable for diesel, gasoline, and multi-valve fuel engines

Highlighting Features of 5w40

Choosing between 5w30 vs. 5w40
Buying the right motor 5w30 vs. 5w40. (Photo: THMotorsports)

The 5w40 is crude-based motor oil that is best fit for diesel and gasoline engines. This motor oil is usually used for cars that are under warranty. Here are some important features of this category of oil:

  • Suitable for vehicles that use unleaded and leaded gasoline

  • Low volatility

  • Helps to reduce oil utilization

  • Excellent thinning resistance against heat

  • Comes with multiple approvals

What Is The Difference Between 5w30 and 5w40

When you go to car maintenance or change the oil, you are often advised by two types of engine oil, 5W-30 and 5W-40, and some drivers think they are the same. Basically, these are two common types that are used commonly, but if you are in the automotive industry, or have knowledge of auto parts, you will see the difference between these two oils. To decide which type of oil is best for your vehicle, here are some key differences mentioned below:

1. Viscosity

This term is defined as how well the liquid will flow through the engine. The working viscosity of 5w30 is basically from 9.3 to 12.5mm2/s whereas the operating viscosity of 5w40 is 12.5 to 16.3mm2/s. That means 5w40 has larger viscosity than 5w30. So, 5w30 is better than 5w40.

2. Fuel economy

When compared in terms of fuel efficiency, 5w30 is more fuel economical than 5w40. It works amazingly fine with an extensive set of vehicles having different engine kinds.

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3. Price

If we compare the cost of both these motor oils, 5w30 is comparatively more than that of 5w40. However, it is worth every single penny.

4. Temperature range

You can use 5w40 in the temperature range of -25OC to 35OC. On the other hand, 5w30 is used in the temperature range from -25OC to 35OC. To explore more about the temperature range of these motor oils, you can refer to maintenance tips by car experts.

5w30 vs 5w40 – Which One is Better?

As we compared above, you also see that the 5w-30 is superior, although sometimes, the price is a bit high. But I think all drivers are thinking about long-term and durable driving, so starting a little shouldn’t be a problem, right? However, when choosing engine oil, you have to solve the problem between performance and protection. The more viscous the oil is when the engine is running, the better it will protect the engine, but if it is too thick, it will be difficult to guarantee the engine’s performance. Normally, the 5w40 is often applied for high-performance engines, with high operating temperatures, and heavy loading. 

For vehicles that are not designed to drive at high loads. 5w30 is the best option for you in this situation. 5w30 will clean the engine better, provide better protection, and have a longer lifespan due to its lower temperature range. Drivers should consult the vehicle owner’s manual to choose the exact viscosity grade for the car. 


Can we mix 5w30 vs 5w40 in the engine?

It is best not to mix oils of different viscosities. In the short term, this does not cause engine damage. So you can add more if the oil level gets too low or in some emergent situations. However, we don’t recommend that you do that more than once. You need to replace it with the oil specified by the manufacturer as soon as possible for optimal engine protection.

Is it possible to use 5w40 instead of 5w30? 

In most cases, 5W40 can be used instead of 5W30. Although it won’t hurt your engine, it can probably affect the oil consumption in the car.  However, most modern cars and trucks use variable valve timing and lift is controlled by oil pressure. In these vehicles, you should adhere to the viscosity grade recommended by the automaker, because the viscosity can affect the oil pressure, thereby affecting the operation of the above components. In older models that do not equip with the above technology, you might use 2 types of oil for each other in case of emergency.

Which oil is better for using in winter: 5w30 or 5w40? 

Based on the viscosity grade, you can notice that 5w30 oil will be more liquid while the 5w40 is more viscous and thicker so that is why 5w30 will protect your engine better in winter or cold weather and 5w40 is always recommended to use in the warmer weather. However, with the viscosity range of 5w30, it’s also proved that this type of oil can be both used in winter and summer.


So, when it comes to picking the right motor oil 5w30 vs 5w40, the former is clearly the winner. The 5w30 motor oil operates smoothly with any engine type regardless of the temperature and provides better protection and lubrication.

Next time you wish to buy motor oil for your vehicle, go for 5w30.

Check out this video to get some basic knowledge about Engine Oil Codes explained: