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The 5W30 Oil Guide (What It Is + Uses + FAQs)

October 27, 2021

5W30 oil is one of the most popular oil viscosity grades in the market today. It’s a top recommendation for passenger cars, SUVs, and light trucks. 

But why is it such a popular motor oil? 
What is 5W-30 oil good for? 

In this article, we’ll discuss 5W-30 oil in detail. 
We’ll look at whether it’s suitable for heavy-duty use and diesel engines, and if it’s a synthetic or conventional motor oil. We’ll also see how it’s different from all the other multigrade oils.

This Article Contains:

Let’s begin! 

What Does 5W-30 Mean In Oil?

The Society of Automotive Engineers (SAE) developed a standard scale to grade motor lubricant and transmission oils by their viscosities. It follows the “XW-XX” format.

In the case of SAE 5W-30 oil, the number preceding the W (i.e. 5) denotes the oil flow at 0°F. The lower this first number is, the better the oil will perform in winter (by not thickening). The ‘W’ stands for winter. 

The numbers after the W stand for the oil viscosity rating at high temperature (212°F). The higher this number, the better resistance the oil will have against thinning at a high temperature.

What Is 5W-30 Oil Good For?

5W-30 oil is primarily a winter viscosity grade motor oil
While it does perform adequately at a higher temperature, its best use is for people who drive in cold temperature regions. 

Due to its lower viscosity, it’s typically recommended for petrol vehicles or a light-duty diesel engine.  Apart from these functions, 5W-30 multigrade oil is also used for the following purposes: 

Now that we know what 5W-30 oil is for, let’s look at some of the most frequently asked questions about this motor oil.

5 FAQS About 5W30 Oil

Here’s a bit more about the 5W-30 oil and its characteristics. 

1. How Is 5W-30 Oil Different From Other Engine Oils?

5W-30 oil has a better low temperature viscosity grade as compared to, say, 10W-30 oil. As a result, the 5W-30 is less viscous in cold temperature settings. 

The low viscosity of this oil means it doesn’t thicken at a colder operating temperature and flows smoothly through the engine without causing friction. 

Compared to other oils, the 5W-30 viscosity grade performs better during winters, preventing car engine wear and tear (thanks to anti wear additives). 

5W-30 oil can operate in temperatures as high as 95°F, after which you should switch to a better high temperature oil viscosity grade. 

5W-30 oil is unsuitable for extremely high temperature use since, at these temperatures, car engines require a thicker oil with proper bearing support and cushioning. As 5W-30 oil is comparatively thinner than any other multigrade oil like 5W-40, it may not lubricate the engine well.  

2. Is 5W-30 Oil Suited For Heavy-Duty Use?

Generally speaking, 5W-30 oil is recommended for petrol and light-duty diesel use. 
However, 5W-30 can suffice heavy-duty use if utilized in the appropriate climate (colder temperatures). 

During winters, it can withstand any amount of cold temperature and moderate pressure due to its excellent viscosity. 

Be sure to avoid high-temperature heavy-duty use with this viscosity grade oil. Doing so may result in inadequate lubrication and cushioning under high pressure, and impact fuel efficiency and oil consumption.

3. Is 5W-30 A Synthetic Oil?

5W-30 oil is available as both conventional oil (also called mineral oil) and synthetic motor oil.

What’s the difference? 
SAE 5W-30 synthetic motor oil is prepared by breaking down and rebuilding petroleum molecules to produce refined base oil. To this, various additives are added for maximum engine protection and better engine life. 

In contrast, 5W-30 conventional motor oil uses a base oil consisting of refined crude oil. To this base oil, anti wear additives are added. 

Although conventional oil and synthetic oil share similar properties, synthetic motor oil performs far better than mineral oil

Regarding the oil viscosity grade of 5W-30, brand new conventional motor oil will behave exactly like 5W-30 synthetic oil. Over time, though, it will deteriorate faster and affect engine performance and fuel efficiency. 

5W-30 synthetic oil, on the other hand, is a lot more stable and yields better engine protection, lubricating critical engine parts well. 

Note: Engine oil (synthetic, conventional, or synthetic blend) deteriorates after a point and loses its fuel efficiency. 

While some oils naturally have a high viscosity, you should be able to tell the difference between thick oil and contaminated oil. Dark, sludgy oil and engine deposits are a sign to get an oil change and may affect your engine life. 

4. Is 5W-30 Oil Used In Diesel Engines? 

A diesel engine combusts at a very high compression rate — much higher than petrol engines. Therefore, they require high viscosity or fully synthetic engine oils that can work under a high temperature setting. 

The oil used in the motor should be able to withstand a high operating temperature and pressure while lubricating your engine parts.

While 5W-30 oil is suitable for a light-duty diesel engine, you probably want to go for a heavier and thicker oil for everyday, heavy-duty use (e.g. 15W-40 engine oil).

5. What Are The Benefits Of Using 5W-30 Oil?

5W-30 oil works well with a wide range of car engine varieties and light trucks. This multi grade oil also covers a decent temperature range and is quite versatile. 

So, you can expect the following benefits from using 5W-30 (conventional oil or synthetic):

Closing Thoughts

Even though 5W-30 engine oil is a popular recommendation among mechanics and car manufacturers, each car engine is built differently. When choosing a multigrade oil, remember to check in with your mechanic and consult your car’s manual for any specific oil requirements. 

Using the right engine oil is one of the most important aspects of properly caring for your car — that and regular oil change intervals and maintenance! 

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