5w20 and 5w30 are the two most common types of motor oil used in vehicles. There is confusion in understanding these types of oil to the extent that others use them interchangeably. However, there is a significant difference in the types of oil that is mainly attributed to its viscosity, that is, the ability to flow or the thickness of the oil to flow against friction.
Given this difference in viscosities, these types of oils are the most suitable for use in different conditions. The article unfolds the key differences between 5w20 and 5w30.
What is 5w20?
5w20 is a common type of motor oil well suited for colder climates. The number before “W” refers to the oil’s winter viscosity rating (W), while the number “20” after “W” is a reference to a 20 weight oil in warmer temperatures. In other words, 5w20 lubricates the engine like a 20 peso oil. The 5w20 works well during low and freezing temperatures as it experiences less friction and drag to flow to deeper engine components because it is thinner. The higher the number, the higher the viscosity, therefore 5w20 is more free flowing than 5w30.
Starting the engine in colder weather requires a thinner oil that can quickly lubricate parts. Due to its lower viscosity, 5w20 is linked to optimal fuel efficiency and performance in cold weather. However, when the engine warms up to normal operating temperatures, 5w20 begins to lack the viscosity needed to protect engine parts for a long time, so 5w30 is more preferable. In contrast, 5w20 will break down easily in hotter climates, thus exposing engine parts to wear. At 100 degrees Celsius, the viscosity of 5w20 is rated at 8.9 and that of 5w30 is rated at 11.0. And at 40 degrees Celsius, the 5w20 is rated at 49.8 and the 5w30 is rated at 61.7. This shows the effect of heat on the viscosities of motor oils.
What is 5w30?
5w30 is recognized as the best motor oil at warmer temperatures compared to 5w20. It is the type of oil characterized by a higher viscosity, that is, its thickness. You experience a lot of friction and more resistance when flowing. As a result, it takes time to lubricate engine parts in colder climates. An engine running on 5w30 may experience delayed starting during the winter. Also, you may experience hiccups. Thicker motor oil is not preferred in colder climates due to its inability to flow easily and quickly to all engine components in a short period of time. As a result, fuel efficiency will be compromised.
When the engine has warmed up to normal operating temperatures or the vehicle is driven in hotter environments, 5w30 is a preferred type of motor oil. This is due to its thickness which provides overall protection to engine parts and better performance. Its 5w20 counterpart would break down in summer temperatures. The meaning of the XwY formula in 5w30 is the same as in 5w20. The 5 before the “W” refers to winter viscosity index and the 30 refers to its lubricity compared to a 30 weight oil in warmer conditions. The higher the number, the higher the viscosity, so 5w30 is thicker than 5w20.
Both 5w20 and 5w30 motor oils have the same design viscosity during winter but differ with weight during warmer temperatures. 5w20, despite the same design viscosity, gets thinner due to less friction in the engine components. There is not necessarily a clear winner among these motor oils as they perform better in different climates. In the long run, 5w30 tends to have more benefit as it provides overall protection compared to slower starts in colder climates. 5w20, on the other hand, would expose engine parts to wear and tear, as it breaks down quickly due to its thinness in hotter climates.
Key Difference Between 5w20 and 5w30
Definition of 5w20 vs. 5w30
5w20 is a type of motor oil characterized by its winter rating of 5 and an oil weight of 20 in warmer conditions. It is less viscous compared to 5w30. 5w30 has the same viscosity index of 5 during the winter but an oil weight of 30 in hot conditions, therefore it is thicker.
Working conditions for 5w20 vs. 5w30
5w20 works well in cooler climates. It allows the vehicle’s engine to start quickly as it flows quickly and smoothly into deeper engine components with less friction. Quickly lubricates parts. 5w30, on the other hand, is working efficiently in hotter climates. Does not thin quickly due to heat exposure compared to 5w20. As a result, 5w30 offers better overall protection to engine components at normal operating temperatures.
5w20 performance vs. 5w30
Both of these motor oils perform efficiently in their designed climates. 5w20 is a champion in colder climates with faster engine starts due to its low viscosity and less friction on engine parts. 5w30 is also a champion in hotter climates where a thick oil is needed to withstand the higher temperatures. The engine will inevitably run hot and therefore require a more viscous oil. In colder climates, 5w20 is linked to fuel efficiency and better performance, while 5w30 is linked to better overall protection of engine components.
5w20 vs. 5w30: Comparison table
Summary of 5w20 vs. 5w30
- 5w20 is less viscous while 5w30 is more viscous
- 5w20 is more preferable in winter where it flows easily and quickly to lubricate engine parts so that the engine starts quickly
- 5w30 is thick to flow quickly during winter climates to start the engine faster. The colder the temperature, the more viscous the liquid.
- 5w20 thins quickly in hot conditions, so it is not preferable in hotter climates. 5w30, on the other hand, is still thicker than 5w20 at higher temperatures.