Difference Between 5W20 and 10W40 (With Table)

The most essential thing that is used in car service is engine oil. It keeps the engine cool. Different engines require different engine oils to function and operate normally. A good oil will also increase the lifespan of the engine.

5W20 vs 10W40

The main difference between 5W20 and 10W40 is that 10W40 is more viscous than 5W20. On the other hand, 5W20 is less viscous than other oils. 5W20 has a lower viscosity and it is also thinner than 10W40. This two-grade engine oil suits different environments and types of vehicles.

Difference Between 5W20 and 10W40

5W20 has a viscosity of 5W, and it is known as a very low viscosity. This oil is thinner compared to any other oil. But it is used in cool temperatures, especially in winter. As mentioned earlier, 5W20 provides better engine performance and lubrication during winter (in low temperatures) because its viscosity is low and will not freeze in low temperatures. 10W40 has a high viscosity and is thicker than other engine oils like 5W20.

10W40 is a synthetic type of multi-grade motor oil with high viscosity and density. This oil is much thicker than any other oil, including 5W20. It performs better in high temperatures as it does not get lighter in warm weather because of its high density. It is also used for cars with high mileage and is especially known for its better performance in the engine part of any vehicle. But the only problem is that it can’t be used in cool weather with a very low temperature. Then we have to switch to other engine oils which work properly at low temperatures (like 5W20).

Comparison Table Between 5W20 and 10W40

Parameter of Comparison5W2010W40
Definition5W20 oils are multigrade oils with very good flow properties at low temperatures.5W20 oil is primarily a winter viscosity grade oil.10W40 is the viscosity, or weight, of the motor oil, as defined by SAE, and has a viscosity grade of 10W at a low temperature and 40 at a higher temperature.
ViscosityLow viscosity.High viscosity.
Working temperatureUsed in low temperatures (winter).Works in high temperatures (warm weather).
AdvantageIt can perform in different temperature ranges.Better wear control, viscosity, low-temperature fluidity, deposit control, and used for high mileage.

What is 5W20?

“5W” in 5W20 means the oil is suitable for winter temperatures down to -35 °C. As 5W20 is a low-viscosity oil, it’s best suited for cars that drive a lot in low temperatures and colder climates. It’s ideally recommended for light-duty petrol and gasoline engines & helps with engine deposits. This oil is available as conventional and synthetic variants. 

This conventional oil is made of refined crude oil and several additives, and at normal operating temperatures, it provides adequate performance. It is also recommended for engine protection and lubrication. 5W20 is synthetic base oil (refined and modified hydrocarbon atoms) and additives. The synthetic base oil and various additives make it comparatively more stable in hotter climates.

It can better handle extreme temperatures and help with engine cleanliness, protecting against wear and tear. Synthetic motor oil will also last longer when compared to conventional oil. While 5W20 oil claims to help with fuel efficiency and reduce oil consumption, it depends on the engine type. An older engine will have a higher oil consumption rate but will also be more vulnerable to engine wear due to grinding gears. Ideally, 5W20 should work as a high-mileage oil as long as it suits the engine.

What is 10W40?

10W40 is the viscosity or weight of the motor oil as defined by the Society of Automotive Engineers (SAE for short). This type of oil has a viscosity grade of 10W at a low temperature and 40 at a higher temperature. It behaves like a 10W weight oil when cold and a 40-weight oil when hot. It would prevent engine wear and tear more effectively in warmer temperatures. 10W40 engine oils are mostly synthetic blends.

Their base is refined crude oil with additives. It will not be long before full-synthetic variants become the standard, as the market is moving in that direction. This oil is recommended for newer vehicles and driven in warmer weather. This type of oil can operate under a working temperature as high as 104 degrees Fahrenheit, while the maximum oil’s working temperature is 85 degrees Fahrenheit.

10W40 is preferred if it puts heavier loads on your engine, such as in commercial vehicles. The thickness of 10W40 is equipped to deal with the increased load and prevents metal-to-metal contact inside the engine. High Mileage 10W40 Mobil 1 motor oil is preferable when using high mileage vehicles (even those that have used lower quality conventional oils), including cars.

Main Differences Between 5W20 and 10W40

  1. The main difference between 5W20 and 10W40 is that their viscosity is different. 10W40 has a higher viscosity than 5W20.
  2. They both work under different temperatures. 5W20 can also work at -35 degrees centigrade. 10W40 is mainly used in high temperatures, but 5W20 is mainly useful in winter (in low temperatures).
  3. 5W20 is much thinner, so it doesn’t freeze in low temperatures and works fine in winter. As 10W40 has a higher viscosity, it is also thicker.
  4. These two oil types are useful in different types of cars and for different purposes. 5W20 is used for vehicles to work in cold temperatures, but 10W40 is mainly used for high mileage and better performance.
  5. 5W20 is ideally recommended for light-duty petrol and gasoline engines. But, 10W40 is designed for lubricating older parts to make them perform optimally.


After going through the features and different kinds of oils according to the temperature, it can be concluded different oils are made and used for different purposes. Oils must be used according to the needs of the engine of vehicles.

Vehicles driven at low temperatures especially in winter, can’t use 10W40 as it might not work appropriately, and parts of the engine might get stuck. But, in that environment, 5W20 can work fine. By following these terms, one should choose the perfect oil for their vehicles according to the environment, depending upon the use of the engine. 10W40 is better than 5W20 for high mileage and better performance.


  1. https://rosap.ntl.bts.gov/view/dot/11836
  2. https://journals.sagepub.com/doi/abs/10.1177/09544089211036227
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