10w30 Vs. 5w30: Main Differences With Respective Usages

Based on the viscosity of the oil, the Society of Automotive Engineers (SAE) has assigned a numerical number to engine oil. The performance of the engine largely depends on the viscosity.

5w30 and 10w30 are those two assigned numerical numbers by SAE. And we will talk about all the key factors between 10w30 vs. 5w30 in this article. 

As a rule of thumb, thicker engine oil has a higher grade and vice versa. But I will talk more about their differences. Stay with me.

Difference Between 10w30 And 5w30

10w30 vs 5w30

The main difference between 10w30 and 5w30 lubricating oil is their viscosity. As the grades indicate, 10W30 engine oil has a higher viscosity than 5W30 engine oil.

And when it comes to the lower temperature, 10W30 engine oil is thicker than its counterpart 5W30.

As 5w30 is much thinner than 10w30 because of the low viscosity, it can protect the inner components of the engine faster and better. 

5W30 is ideal for areas where the temperatures get -30 degrees Celsius and where the temperature can reach up to 35 degrees Celsius.

On the other hand, 10W30 works in a smaller temperature window like -18℃ to 30℃.

For light-duty engines, 5W30 engine oil is ideal whereas to carry heavier loads, 10W30 is perfect. More so, because it’s thicker, 10W30 can provide the sealing action in the engine.

But when it comes to performance, both of them will perform the same at operating or high temperatures because of the same SAE 30 rating. But don’t forget, 5w30 is much suitable for the cold season!

So, which one provides better lubrication?

Well, due to the better flow rate, 5w30 can lubricate the engine parts better than the 10w30.

And if the lawnmower or your car has light-duty diesel or petrol engine, 5w30 is better suited. For commercial vehicles with heavy load engines, 10w30 is better suited.

Sounds complicated?

Let’s define both grades first before checking their differences. You will also learn how they are graded as well.

What Is 5w30?

5w30 refers to the viscosity grade of 5 at lower temperatures and for the higher temperature, the viscosity grade is 30. 

It meets Volkswagen (VW) and Mercedes Benz’s specifications that differ from brand to brand. Depending on the brand, it also meets the specification of Ford and Porsche oil specifications.

Benefits of 5w30 Engine Oil

5w30 engine oil

It’s suitable for light-duty diesel engines, automotive gasoline engines, light-duty petrol engines.

Meaning, you can use it for your lawnmower and pressure washer as well.

As it can give a good flow in low temperatures, it’s perfect for any engine in cold climates. It reduces the friction among engine parts creating a continuous layer over the parts.

Apart from friction reduction, it protects the engine from rusting and enhances the engine life reducing wear and tear too.

The reason it can increase the lifecycle of the engine is because of its superior thermal stability as well.

Because of this stability, the properties remain the same even if the temperature varies. 

And it takes a small amount of oil to lubricate the engine. That’s because it’s designed that way to keep the oil consumption at a minimum.

What Is 10w30 Engine Oil?

By now you should be able to what 10w30 refers to, right?

Like the previous one, it’s multi-grade engine oil that has 10 viscosity grades for lower temperature and 30 for higher temperature.

A while back, I have written an in-depth article on the difference between 10w30 and SAE30. I have explained in detail about the 10w30 engine oil there. 

In summary, it has a low viscosity grade at a lower temperature because the oil becomes thin at such a low temperature.

If you decide to get 10w30 for your engine, make sure to look for the viscosity grade and API SN, ACEA ratings.

Such ratings indicate that the oil is capable to protect the engine’s piston from the deposits by the fuel combustion. And to be able to get those ratings, the oil must have good sludge control. 

Benefits Of 10w30

Like the 5w30 oil, it also creates a continuous layer over the engine parts to reduce the friction among them.

It also prevents the rapid wear and tear of the engine from the start and stops operation keeping the engine cool.

For the noiseless operation of the engine, it enables the smooth operation of the gear and the clutch.

Even when the temperature changes, it’s capable of maintaining its viscosity. Also, like the 5w30, it increases the engine life protecting it from getting rusted. 

Watch the friction testing video of 10w30 engine oil.

When to Use 10w30 And 5w30 Engine Oil?

The engine of your lawnmower, pressure washer or car has lots of moving parts. Such parts are subject to friction when the engine is running. 

Without any lubricating substance, such frictions can lead to wear and tear of those parts and the ultimate damage to the engine. 

But it will damage your engine more if you use the wrong oil grade. So, it’s crucial to understand when you should use what grade for the sake of the engine.

The cold flowability is the main difference between the two, right?

Now, think about exactly which one to use depending on the temperatures the engine will operate. 

If it gets really cold during the winter, or you live in a place where it’s usually cold, use 5w30 engine oil.

Use 10w30 grade engine oil if it’s summer or the temperature is usually hot.

You will be needing even higher viscosity oil like 15w40 if you live in a tropical area where the temperature is consistently high.

Now, things get even more complicated, right?

Well to make it easier for you, use the manual that comes with your lawnmower, pressure washer, or car to figure out the right viscosity oil.

Always follow the recommended weight of the oil as recommended by the manufacturer. Using the wrong oil grade will result in trouble for the engine.

Engine oil with too high viscosity will lead to increased drag and excessive oil temperatures. 

On the other hand, oil with too low viscosity than the recommended grade will lead to the metal to metal contact and fast wear and tear of the engine.

To be on the safe side, it’s wise to use the oil range specified by the manufacturer.

That way you can ensure that you are using the right viscosity and your engine will keep performing well.

Also Read: Difference Between 5W30 And 5W40.

How Engine Oil is Graded?

Before the development of the thickening additives, oil manufacturers would produce single-grade oil only. 

As the single grade oil used to have only one viscosity, they were labeled with only one number like SAE10. 

Back then, the heavy engine oil would protect the engine well during the summer but it would get problematic during the wintertime.

To solve this problem, automotive oil manufactures now produce multi-grade engine oil. Depending on the temperatures, such multi-grade oil behaves differently. 

The viscosity numbers you see nowadays are based on a test developed by the Society of Automotive Engineers (SAE). 

So, how they determine the viscosity?

Well, the viscosity of the oil is determined by the number of seconds the oil takes to flow through a specific size tube. 

All the engine oil thickens during the winter and becomes thin during the summer. So, the first viscosity number ‘w’ refers to winter and it is tested at 0°F. 

To simulate the heat of the engine, the second number is tested at 212°F. Let me give you an example.

So, when engine oil is graded as 10w30, what does it mean?

It simply indicates, when it’s cold, it takes 30 seconds for the oil to flow through the tube. And it takes 10 seconds when it’s hot.

Frequently Asked Questions (FAQs)

Can 10w30 be used instead of 5w30?

It’s not recommended but mixing them won’t hurt the engine since both have similar synthetic. Also, as both have very close viscosity, mixing them won’t leave any effect on the engine.

Should I use 5w30 or 10w30?

That depends on where the engine will be during the certain season. If it’s going to be in the winter, you should use 5w30 engine oil. 10w30 is suitable for hot temperature.

However, if the temperature never goes below zero, both grades of the oil is okay to use.

When should I switch from 5w30 to 10w30?

As both of them differ only in cold weather viscosity, no need to switch if the temperature never goes below the zero degree Celsius.

Is thicker oil better for older engines?

In short, yes. Thicker oil can prevent the older engine better from friction and oil loss than thinner oil. New vehicles will be better off with thinner oils.

Will 5w30 hurt a 10W30 engine?

Yes, it will. Although both oils are same at the operating temperature, starting the engine during the winter or summer requires different grade oil.

Closing Remarks

The main purpose of writing this in-depth 10w30 vs. 5w30 article is to give you a clear understanding of their key differences. 

That clear understanding will protect against friction and give your engine a prolonged life. 

If you still have some confusion regarding the difference between 5w-30 and 10w-30, let me know in the comment box.

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