Can I Use Sae 30 Instead Of 5w30 & Vice Versa? [Answered]

Thinking about using sae 30 as an alternative to 5w30? But not quite sure if you should do it or not. We know the dilemma you are facing. Furthermore, using the wrong oil can create engine problems.

So, can I use sae 30 instead of 5w30? 

Yes, you can use it as an alternative. They have the same viscosity at operating temperature. But at lower temperatures, sae 30 becomes more rigid. Because it is a single-grade oil and does not have a winter oil rating. So, you have to keep the oil temperature over 50°C always. Only that way you can use sae 30. Otherwise, it’s best to avoid this. 

Anyhow, this is only the overview on this topic. But for better understanding you need details. Thus, here we have tried to compare both of them in detail. 

Let’s not waste any time and hop right in!

Sae 30 Vs 5w30: Overall Comparison

Sae 30 and 5w30 are the two different types of engine oils. The sae 30 is a single viscosity oil without any winter rating. Whereas, the 5w30 is a multi-grade oil with two different viscosity ratings. 

Now, it is really important to know the detailed comparison of these oils. Being ignorant of this matter can be detrimental to your machine.

Here, we have prepared an overall comparison between them-

Categories5w30sae 30
Viscosity (at cold temperature)LowerHigher
Viscosity (at operating temperature)SameSame
ApplicationCar EngineLawnmower
Engine Protection (at cold temperature)HigherLower
Engine Protection (at operating temperature)Same Same 

As you can see a brief comparison between them. Let’s check the elaborated discussion-


What is viscosity? We know this is a bit of science-related stuff and can be difficult. There is no need to worry! We will try to explain it as simply as we can. 

Viscosity expresses how much resistance a fluid will show while flowing. A fluid with higher viscosity will show more resistance while flowing. It happens because the moving fluid has internal friction.

Oil rating indicates its viscosity. If yours has a higher oil rating that means its viscosity is high. Meaning it will resist the natural flow of the fluid more.

Now, sae 30 and 5w30 have the same viscosity in operating temperature. That means you can use one instead of the other at higher temperatures.

But the problem occurs at lower temperatures. sae 30 doesn’t have any oil rating for winter. What does that mean? It means under colder conditions this will still have a viscosity rating of ‘30’. This is a really high oil rating in cold climates. It’ll barely flow inside the engine. 

On the other hand, 5w30 has a winter rating of ‘5’. This is much thinner and easily flows inside the engine at lower temperatures. Thus, making it much better at colder conditions among the two of them.

Therefore, you should not interchange these oils if you stay in a colder climate. But if the surrounding temperature is high, you can replace one with the other.


The thickness of oil is closely related to its viscosity. The oil will be thicker if the oil rating number is higher. So, the lower oil rating will mean the oil is thinner. Thicker oil tends to have more hindrance while flowing.

Sae 30 and 5w30 both have the same thickness at operating temperature.

But there’s a catch! This similarity of thickness vanishes at a lower temperature. At lower temperatures, the 5w30 becomes much thinner. In contrast, the sae 30 stays the same as in operating temperature. 

This means the sae 30 will face more resistance while flowing. As a result, the flow of the oil will be less spontaneous. Because when the oil cools down, it becomes less slippery.

Whereas, the 5w30 under low temperatures will flow more easily. This comparatively better fluidity results in better performance in colder conditions.

So, by never letting the temperature of the oil cool down you can interchange them. But if you stay in colder conditions, it’s better not to use sae 30.


Firstly, let’s talk about the sae 30 oil. It is often suggested that it should be used in small engines. This oil is mostly used in generators, lawnmowers, various 4-stroke garden tools.

The sae 30 has a tendency to solidify at lower temperatures. So, you should not keep it inside your tools for a long time. While using this oil, make sure you only fill the tank prior to use.

On the contrary, the 5w30 is much more flexible. It is normally used in car engines under higher temperatures. 

As it has a winter oil rating, it does not solidify under low temperatures. So, you can keep the oil inside after you are done using your vehicle. Even while operating, you can fill your tank with this oil. Because it is a multi-grade oil.

To sum up, for smaller engines of 4-stroke garden tools sae 30 is better suited. But for heavy-load engines,  5w30 will perform better.

Engine Protection

Usually thicker oil offers better support to the engine. The 5w30 flows rapidly inside the engine. This protects the engine from wear and the engine runs smoothly.

However, the sae 30 will offer the same protection at higher temperatures. But things become complicated under lower temperatures.

The flow becomes less rapid. This means the oil doesn’t reach different parts of the engine fast. This results in more wear to the engine.

As there is more wear, the engine performs at a lower level. Meaning, the engine will not provide the expected output.

Hence, for engines’ safety and better output don’t interchange the oil at lower temperatures.

Can I Use 5w30 Instead of Sae 30?

If you’re curious about this, the answer is the same. You can use 5w30 instead of sae 30. At operating temperature, both of them have the same viscosity. As a result, there will be no glaring issues in your engine.

But if you think about the application of the oil. Normally, the oil used in a lawnmower is different from the one used in a car. The sae 30 is usually used in smaller engines. That’s why the manufacturers provide recommendations for engine oil.

To be fair, using the right oil is always good for your engine’s longevity. But sometimes we can be pushed into the corner.

What Happens If I Put Sae 30 Instead of 5w30 and Vice Versa?

Till now it’s clear that you can use sae 30 instead of 5w30. Because the viscosity rating of both oil at operating temperature is the same. So, they don’t have many differences at a higher temperature.

But make sure to keep the engine oil temperature above 50°C always. Because if the temperature falls under that, the oil starts turning into solid.

Using sae 30 instead of 5w30 can result in accelerated wear. The engine will get less protection and become weary. This will result in lower performance output and less efficiency.

Also, by changing to 5w30 from sae 30 won’t really damage the engine. However, if your car requires 5w30, you should stick to 5w30. Otherwise, your car won’t function properly due engine issues. 

What Is a Better Alternative?

The thought of using sae 30 instead of 5w30 can be really worrisome. This conundrum may go away if you try out this alternative method. You can mix your sae30 oil with a bit of 5w30 oil.

Are you surprised all of a sudden? Wondering: can I mix sae 30 with 5w30 without harming my car engine? 

Well, don’t worry at all! Mixing the two oil types won’t harm the car engine. Because these oils don’t have any difference in viscosity under operating temperature. This makes them a compatible set. 

But always remember, this should be done rarely. Apply this trick only if you don’t have anything else to do.


Question: Will 5w30 hurt my lawnmower?

Answer: Theoretically, it won’t hurt your lawnmower. Under lower temperatures, it will work perfectly. The issue might occur when it’s too hot. The oil may become too thin to lubricate your lawnmower properly.

Question: Will my oil go bad while sitting in an engine?

Answer: The straightforward answer is no. It will stay good especially if you change it right before storing the car. It is the same as staying in a plastic bottle. But sediment may settle in if your car is stored for a long time.

Question: What is sae 30 equivalent to in ISO VG?

Answer: ISO VG and sae use different parameters to measure viscosity. In ISO VG, ISO 100 is equivalent to sae 30. ISO 46 is equivalent to sae 20, and sae 30 is equivalent to ISO 100.


Well, this is where we part ways. We tried to present everything we could on- can i use sae 30 instead of 5w30.

Hopefully, we helped in solving your dilemma. You can always try the alternative if it’s really necessary.

Good luck!

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