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The 10W30 Oil Guide (What It Is + Uses + 4 FAQs)

October 29, 2021

10W30 oil is a popular multi grade oil commonly used in heavy-duty petrol and diesel engines. 

That said, is 10W-30 an oil grade option for you?
And how is it different from other viscosity grade oils? 

In this article, we’ll look at 10W-30 oil in detail — including its uses, whether it is synthetic or suitable for high mileage use. We’ll also look at how it is different from other oils and if you can use 10W-40 instead of 10W-30 oil

This Article Contains: 

Let’s begin! 

What Does 10W30 Mean In Oil?

A multi grade oil is engineered to carry the properties of two different viscosity grade oils. In this case, the SAE 10W and SAE 30 weight oil.

But what does that mean? 
The numbers before the ‘W’ represent the oil’s winter-grade viscosity. The lower this number is, the better your engine oil will perform in cold temperature environments. 

The numbers after it denote the oil viscosity at high temperature settings. The higher these digits are, the better they’ll hold up under a hot operating temperature. 

Meaning, 10W-30 motor oil acts like an SAE 10W weight oil under 0°C (32°F), and an SAE 30 oil at 100°C (212°F). 

10W-30 oil can survive in a temperature as low as -13°F and as high as 86°F. This makes 10W-30 oil pretty stable at higher temperatures and pressure, and can run through critical engine parts without causing too much friction. 

However, it’s a comparatively thicker oil and has a consistency similar to grease. So, it may not perform as well in extremely cold climates and lower temperatures. For those cases, you may want to look for a thinner oil like 0W-20 or 5W-30.

Keeping that in mind, let’s take a look at what 10W-30 multi grade oil is used for. 

What Is 10W-30 Oil Used For?

10W-30 has a great capacity to withstand hotter temperatures without compromising the quality of the engine performance. It can also work well under high temperature and pressure environments in hotter climates and adhere to the engine without thinning out. 

This makes it ideal for heavy-duty diesel engines since it is a slightly thicker oil with a heavy-loading capacity. 

This lubricant protects engine parts like pistons from forming engine deposits. It also prevents engine damage caused by friction and insufficient lubrication. 

Apart from these basic functions, 10W-30 oil also features:

Now, let’s find out more about 10W-30 lubricating fluid through some common queries.

4 FAQs About 10W30 Oil

Here are some frequent queries about the 10W-30 lubricant and their answers:

1. Is 10W-30 Oil A Synthetic Oil?

10W-30 engine oil is available in conventional (mineral oil), synthetic, and synthetic blend variants. Naturally, synthetic motor oil outperforms all other fluid variants of 10W-30 oil at normal operating temperature. 

Mineral oil is made using refined crude oil as the base oil and several additives. While it’s far cheaper than others, it is less stable than synthetic oil at high temperature settings and breaks down faster.

As such, a synthetic 10W-30 may even perform better than 10W-40 mineral oil at higher temperatures. And you can expect increased fuel efficiency and greater fuel economy. 

10W-30 oil is also available as a synthetic blend motor oil. Synthetic blend 10W-30 has some characteristics of full synthetic oil to protect the internal combustion engine and ensure smooth engine function.

That said, remember to always consult your mechanic before switching between conventional and synthetic motor oil during an oil change if your car requires a specific oil type. 

2. How Is 10W-30 Oil Different From Other Oils?

If you’re comparing the 10W-30 lubricant to an even higher viscosity oil (like 10W-40), 10W-40 will be thicker at higher temperatures and adhere to the engine better. In contrast, 10W-30 will flow more smoothly without leading to a lot of friction caused by engine drag.

Compared to lower viscosity oils (like 5W-30 or 0W-20), 10W-30 performs far better at hot temperature settings. However, it won’t hold up as well in low temperature climates or cold weather. It will likely interfere with your car’s start-up performance at lower temperatures.

This also means that your engine will experience increased oil consumption and lower fuel efficiency. Light trucks and passenger cars may face overexertion due to the increased strain caused by heavier oils (like 10W-30) in cold climates. 

Note: When choosing an oil grade for your car, make sure your oil is API-certified and suited to your vehicle. Most cars require a specific oil viscosity grade. Consult your vehicle manual and car mechanic to find the right oil for your car.  

3. Can I Use 10W-40 Instead Of 10W-30 Oil?

In most cases, no, you can’t. 

Most engines are designed and tuned with certain oil viscosity, and switching to heavier oils can affect your engine performance. 

Some cars may allow a little flexibility for motor oil, but it is best to check with your car mechanic before making the switch. 

In the case of older engines, automakers usually recommend using thicker oil to coat their critical engine parts properly. However, if your car demands 10W-30 oil and you use 10W-40 instead, you may be putting too much pressure on your engine.

Keep in mind that you should always refer to the suggested oil viscosity for your engine. Using high-viscosity oil for older petrol or diesel engines may unnecessarily stress the engine parts and lead to friction.

For example, using heavier oils like 10W-40 for light trucks or passenger cars may exert too much strain on their engine and cause problems like sludge formation or oil leaks.

4. Is 10W-30 Oil Good For High Mileage?

10W-30 motor oil makes for a decent high-mileage oil. It gives a better fuel economy while reducing the oil consumption for older engines.

Older engines with more than 75,000 miles on them require a thicker oil that will properly lubricate their critical engine parts and prevent oil leaks, sludge, and deposits. 

For high mileage engines, a high viscosity motor oil can help resist the wear and tear of engine parts, and avoid the friction caused by grinding gears on metal surfaces. 

However, before buying a higher viscosity oil, check with your engine manual to make sure it’s not too thick for your engine and won’t cause any problems with its functioning.

Closing Thoughts

10W-30 oil can offer a very versatile operating temperature range for your car, especially in hotter temperatures. 

When choosing the right oil, remember to consult your mechanic and get routine maintenance and oil change for your car’s overall health. If you’re looking for a reliable car repair and maintenance solution with top ASE-certified mechanics, reach out to RepairSmith

RepairSmith is a mobile car repair service that offers competitive and upfront pricing, and a range of maintenance services. 

Fill out this form to enquire about an oil-change service now!