Blog Car Care Advice What Does 5W-20 Mean in Motor Oils?
Car Care Advice

What Does 5W-20 Mean in Motor Oils?

Looking for a mechanic near you for maintenance or repair? AutoNation Mobile Service brings the shop to you. Get a free instant quote today.
Get a Quote

5W-20 oil is a popular multigrade oil known for its excellent start-up performance in cold temperatures and engine protection properties.

But should you be using 5W-20 oil? 

Let’s examine 5W-20 oil in detail, including what 5W-20 means, how it differs from other viscosity grade oils, and if it’s suitable for high mileage cars.

This Article Contains:

What Does 5W-20 Mean in Oil?

SAE class 5W-20 oil is primarily a winter viscosity grade oil. It consists of fully synthetic base oils and selected additives.

Here’s what the numbers in 5W-20 mean:

What’s oil viscosity?
It’s a measure of how thick or thin motor oil is. It determines the oil’s flow properties and resistance to breakdown, particularly at different temperatures and operating conditions. 

Now, 5W-20 oil is relatively thin at very high temperatures, but it still provides decent protection and lubrication at a normal operating temperature in moderate climates. However, you should switch to a higher viscosity grade if you drive a lot in significantly higher temperature settings and hotter climates. 

So what is 5W-20 motor oil good for? 
Let’s take a look.

What Is 5W-20 Oil Good For?

As 5W-20 is a low-viscosity oil, it’s best suited for cars that frequently drive in a low-temperature environment and colder climate. It’s ideally recommended for light-duty petrol and gasoline engines and can help with engine deposits and wear and tear problems. 

For a higher-temperature climate, use 10W-30 as an alternative. 

Apart from its fantastic low-temperature performance, 5W-20 oil helps with the following:

Note: Despite these benefits, you should use 5W-20 oil only when recommended by your car manufacturer and mechanic. Using the wrong motor oil can cause serious harm to your engine and affect engine performance. 

Now, let’s look at some other frequently asked questions about 5W-20 oil and their answers.

7 FAQs on 5W-20 Oil and Other Oil-related Queries

Here’s what you need to know about 5W-20 oil: 

1. How Is 5W-20 Different Than Other Oils?

There’s not much difference when you compare 5W-20 to other winter viscosity grade oils like the 5W-30 oil

For instance, 5W-30 oil will perform slightly better than 5W-20 in hotter climates due to its higher ‘30’ hot viscosity rating. Meanwhile, 0W-20 oil has the same viscosity as 5W-20 at higher temperatures but is thinner and flows faster in a cold start.

But when compared to a higher temperature grade motor oil, like 10W-30, you may notice clear distinctions: 

5W-20 and 10W-30 are also very different viscosity grades and oil flows. 

2. Is 5W-20 Oil a Synthetic Motor Oil?

5W-20 oil is available as conventional, synthetic, and synthetic blend engine oil. 

5W-20 conventional motor oil consists of refined crude oil and several additives. It provides adequate performance at normal operating temperatures and offers better protection and lubrication for the engine.

5W-20 synthetic engine oil comprises synthetic base oil (refined and modified hydrocarbon atoms) and additives. The base oil and various additives make it comparatively more stable in hotter climates.

Synthetic oils can handle extreme temperatures better, help with engine cleanliness, protect against engine wear and tear, and reduce the risk of thermal breakdown. They also last longer when compared to conventional oil. 

5W-20 oil is also available as a synthetic blend oil. Synthetic blend 5W-20 tends to be cheaper than synthetic motor oil, but it protects better and lasts longer than conventional oil. 

3. Can You Use 5W-20 Instead of 5W-30 Motor Oil?

Even though 5W-20 is similar to 5W-30 motor oil, you shouldn’t switch between them.  

Using the wrong lubricant can be detrimental to your car’s engine part. It can cause problems like sludge formation, engine deposits, and even reduced engine life. 

It’s best to stick to the oil viscosity recommended in your car’s manual. While some vehicles are more versatile with their oil needs, most run on particular oil viscosity. Remember to check your oil’s product description to determine if it’s the right oil. 

And, if you accidentally added 5W-30 oil to your engine, contact your mechanic for an oil change ASAP. It won’t cause any immediate damage to your engine, but constant exposure may affect engine performance. 

4. Can You Mix 5W-20 and 5W-30?

Mixing 5W-30 and 5W-20 is generally not recommended and should be done only if unavoidable.

If you must, ensure you mix oils of the same brand and in optimal driving conditions. This means you should not mix the oils if the weather is too hot or cold. 

5. Is 5W-20 Oil Good for High Mileage?

5W-20 should work as a high-mileage motor oil as long as it suits your engine

You need to consider two factors before choosing a motor oil for your high-mileage vehicle.
They are:

While 5W-20 oil claims to help fuel efficiency and reduce oil consumption, its performance also depends on your engine life. For instance, an older engine will have a higher oil consumption rate but will also be more vulnerable to engine wear due to grinding gears. 

If 5W-20 doesn’t work well for your vehicle, use a comparatively thicker oil like 5W-30 or any other suitable high-mileage oil as an alternative. This will protect critical engine parts without causing too much strain.

6. SAE, API, and ILSAC: What Do They Mean?

Here’s a quick overview:

1. SAE
SAE in motor oil stands for Society of Automotive Engineers. They designed the viscosity coding system, and “SAE” refers to the oil viscosity specification. It covers conventional motor oil, synthetic oil, and synthetic blend motor oil. 

A motor oil without “SAE” stated before the viscosity rating might not comply with SAE standards. As such, a non-SAE synthetic oil could be quite different from synthetic SAE oil, even with the same viscosity rating. 

2. API
API refers to the American Petroleum Institute. Conventional motor oil with an API rating means that the lubricant meets the performance standard of auto manufacturers. 

American Petroleum Institute ratings are denoted by either an S or C, where S is for gasoline engines, and C is for diesel. API-rated oils include API SN, API SP, API CK-4, etc. 

International Lubricants Standardization and Approval Committee (ILSAC) is an organization that Ford Motor Company, Chrysler, and others created. It aims to develop minimum performance standards for passenger car engine oils used in gasoline-fueled engines. 

They introduced ILSAC GF 6A to provide new engine oil performance levels for spark-ignited internal combustion engines. ILSAC GF 6A is a thicker oil and provides better protection against engine wear and failures related to turbocharger depositing.

7. What is Oil Breakdown?

Oil breakdown is when a car’s internal heat causes a chemical reaction in motor oil, causing a change in the oil’s viscosity. The high heat level causes the oil to degrade and break down. 

When this happens, the viscosity change caused by thermal breakdown results in a decrease in oil flow. This eventually leads to increased oil consumption, deposit buildup, and damage to the engine’s metal surfaces.

Get Your Routine Oil Top-Ups at AutoNation Mobile Service

5W-20 engine oil can be a great choice for your car. It offers a decent operating temperature range, improves fuel efficiency and engine protection in a cold temperature, and boosts fuel economy. 

The important thing to remember is to get a routine oil change and regular maintenance. This will help prolong your car’s engine life and prevent the failure of critical engine parts.

If you’re looking for a reliable car maintenance solution, contact AutoNation Mobile Service.
We are available seven days a week. We offer upfront pricing, convenient online booking, and a 12-month, 12,000-mile repair warranty.

Get in touch with us, and we’ll fix your car right in your driveway.