5w20 Vs 5w30 Oil What’s The Difference

As you know High-quality Oil is very important for the proper working of any machine. Oil provides lubrication to the parts of the generator and keeps them safe from rust and friction. The right oil for your generator can increase its life span, boost its efficiency, and reduce noise.

There are a variety of oils available in the market but the most common are conventional and synthetic oils.  Similarly, their variants are also available. But the question is which oil is best. As in winter oil viscosity increases and the generator may misbehave due to this reason. We have 2 common multigrade oils 5w20 and 5w30 that are considered best for winter. But people usually confuse these two oils and often use them alternatively.

You will analyze some of the key differences between these two oils and their specifications.

5w20 oil – Specifications

5w20 is a multigrade lubrication oil that is best for use in low-temperature regions. 5W20 oil has a viscosity of less than 5 or equal to 5 at temperatures below 0°C. This implies that in the winter when the weather is severe outside, this oil maintains its viscosity as it is fluid and allows an easy start of the engine. It saves you from the hassle of starting a generator in a frosty environment and your time.

I would recommend you use this oil at approx  -31°F up to 77°F / -35°C up to +25°C. This oil has many benefits as helping in the smooth working of the engine with a noise-free operation. It is best suited for cars, vehicles, and light-duty oil engines.

5w20 oil - Specifications

5W30 Oil – Specifications

5W30 oil is also a multigrade engine oil used to increase the efficiency of the engine. It is suitable for the temperature ranging from -13°F up to 95°F / -25°C up to +35°C. This oil is a bit more viscous than 5W20 oil but is no less efficient than any other oil.

Both oils are almost similar having almost the same viscosity, and the same usage, and are suitable in the winter season when oil gets thin at low temperatures. This oil is best suited for light-duty oil engines and provides smooth working, easy clutch operation, and noise-less running.

What is meant by Viscosity?

To make it simple for you, “viscosity is the measure of liquid resistance to flow”. All the numbers like 5,10,30 show the viscosity level of the oil. The higher the number, the more will be the viscosity. Engines need thick oil for their proper working as viscous oil sticks to the parts effectively whereas thin oil doesn’t work any well.

Viscosity is affected by many factors and the most important is temperature. The higher the temperature, the oil would get thinner, and the lower the temperature, the oil would get thicker. So, for lower temperatures, I would recommend you use 5W30 oil.

For more information, you can consult the owner’s manual to know the suitable oil for your machine.

What does “W” signify?

We have seen that the oil numbers are usually written with the “W” letter. W signifies the word Winter which is these oils are best suitable for winters and their viscosity will remain the same even at the lowest temperature.

What do the Numbers signify?

Numbers play a very important role in knowing the oil viscosity at a lower temperature. For example; in 5W30, 5 signifies the viscosity that oil attains at a lower temperature whereas the number 30 represents the viscosity of oil that it attains while running the engine. So, both the viscosities are very important for their working.

What do the Numbers signify

Difference between 5W20 and 5W30 oil

Both oils are almost the same and have very few differences and we will discuss these differences one by one to make clear every single detail;

General Meaning

According to the Society of Automotive Engineers (SAE), the engine oil viscosity is represented by the ratings 5w20 and 5w30. wherein “W” denotes winter, while the numbers show the viscosity when you start the engine and during the running of the engine. We have tested these multigrade oils and found them to be excellent for the proper lubrication and working of the engine. The higher the temperature lower will be the viscosity and vice versa.

You don’t have to worry about the low temperature as this oil didn’t change its viscosity and works efficiently even at low temperatures. Actually, the thickness of both oils makes a difference. The oil becomes thinner at extremely high temperatures. When there is cold, 5w30 is an SAE 5, and when heated, it is an SAE 30. For 5w20 multi-grade oil, the same holds true. It is naturally thinner than 5w30 oil.

Performance of both Oils

Because both SAE ratings have the same base number so we can assume that both engine oils will function almost similarly. The number 30 is the thickness level that oil attains during the running of the engine. At 100 degrees Celsius, both oils have a similar viscosity, although, in cold temperatures, 5w30 grade oil is thicker than 5w20 grade oil. Because of the narrower temperature range, 5w30 oil will flow well at high temperatures whereas 5w20 oil will flow successfully at low temperatures.

So, I can say that 5W30 oils work great in summer whereas 5w20 oils work great in the winter season.


5w30 and 5w20 are both multigrade oil and work effectively in summer as well as in winter. Before buying these oils must consider the temperature of your area. Temperature directly affects the viscosity of the oil and if oil is thinner you can’t expect good performance from your engine.

5w30 will flow well in hot summers or high-temperature environments whereas 5w20 will work better in winter temperatures.

Is 5w30 thicker than 5w20?

The simple answer is yes! 5w30 oil is slightly thicker or you can say that high viscosity as compared to 5w20 engine oil. 5w30 multigrade oil type indicates that the starting viscosity of the oil would be 5 in winter whereas the operating oil viscosity would be 30. I would recommend you use the 5w20 oil type for your engine, whether it’s the vehicle engine or a generator when there is cold outside. You can use 5w30 oil in summer for better results.

Is 5w30 thicker than 5w20

Can you mix 5w20 and 5w30?

Yes! ! You can use a mixture of 5w20 and 5w30. Both oils have almost the same viscosity and the same operating range. But there is a difference in the density of both of these oils. 5w30 is denser as compared to 5w20. But as both are synthetic oils and work almost similarly so, you can mix them well for your car engine or for any motor.

In summers this mixture is expected to work well but in winter as both oils have different densities so there are chances that the engine would face difficulty in pulling up the oil-damaging parts of the engine. Moreover, the engine should be compatible with this mixture or have the same API service level.

Different-density oils can never mix together perfectly. So, I would recommend you use only one type of oil at a time to make the engine last longer.

5w20 vs 5w30 in hot weather

So, the question is 5w20 or 5w30 which oil is best to use in hot weather? 5w30 oil is best to be used in summer if you have only these two options because it is a slightly thicker oil and maintains its viscosity even at high temperatures. It makes the pulling of oil easy for the engine and because of this precise viscosity, engine parts get properly lubricated and save from any abrasion and damage. For winter, you can use 5w20 oil. 5w20 vs 5w30 oil pressure

Can I use 5w20 oil instead of 5w30 oil?

No, you can’t. If it is recommended by the manufacturer to use 5w30 for a car or any device engine you must use this oil then otherwise it will affect the performance of the engine and makes the oil flow difficult. 5w30 oil is thicker than 5w20 oil and some heavy engines need a higher density oil so don’t make this mistake although they have almost the same viscosity. Sometimes, the slightest things also matter.

5w20 Vs 5w30 Oil – FAQs

How often should 5w30 oil be changed?
According to the experts, the engine oil should be changed after the 500hrs of usage of it. You can also change the oil every season for the efficient and smooth working of the engine. You can check out here how to change the oil in a generator.
Should I use thicker oil in an older engine?
Yes, I would recommend you use thicker oil in older engines as the engines get old it needs Higher viscosity fluid for proper functioning.
Does motor oil have an expiry date?
Yes, usually expiry date is mentioned on the bottle but it is recommended to use oil within 5 years of its manufacturing. Stale or expired oil has less performance and oil changes its viscosity.
Is 5w-20 oil synthetic?
Yes, 5w20 is a synthetic oil that is best to be used in winter. Moreover, it provides excellent lubrication to the parts of the engine and keeps them safe from rust and abrasion.
Is 5w20 thicker than 5w30?
No, 5w30 is thicker and has more viscosity as compared to 5w20 oil. Both oils have the same starting viscosity of 5 whereas the operating viscosity is different.


To Summarize

A superb multigrade oil for use in both cold temperatures and hot summer temperatures is 5w30 and 5w20. Due to less drag on the engine’s bearings and moving parts, it is also more fuel-efficient.

Because 5w30 is thicker, it might enable older engines to seal more effectively. Older engines have wider clearances, requiring heavier oil for better protection.

The engine oil recommended in your owner’s manual should be used at all times. You can also read our article on what kind of oil a generator takes for detailed information.

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