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0W-20 Vs 5W-20 Oil (5 Key Differences + 4 FAQs)

December 1, 2021

0W-20 vs 5W-20 engine oil — which one should you use? 

Is there any difference between these oil viscosities? 
If so, which oil performs better?

0W-20 and 5W-20 are both types of multi grade oil, offering several benefits that make them a popular engine oil grade among diesel and gasoline engines.  

This article will focus on the key differences between 0W-20 vs 5W-20 oil, including their hot and cold viscosities, performance, fuel economy, and pricing. We’ll also cover some other related queries

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Let’s begin! 

5 Key Differences Between 0W-20 Vs 5W-20 Oil

0W-20 and 5W-20 are multi grade oil viscosities. 

Each viscosity grade is a value assigned to these oils by the Society of Automotive Engineers (SAE). The W stands for ‘Winter,’ while the numbers before and after represent the oil weight at cold and warm temperature settings, respectively.

These motor oils are usually used as winter viscosity oils, and they both offer a similar, versatile operating temperature range. 

However, you will notice minor differences upon closer inspection:

A. Cold Viscosity 

An oil’s viscosity is the measurement of its resistance to flow. It also refers to the oil’s thickness at various temperature settings. 

0W-20 motor oil acts as an SAE 0W weight oil at cold temperature settings. On the other hand, 5W-20 oil acts as an SAE 5W weight oil.

In SAE terminology, the lower the number before the ‘W’ is, the better the motor oil performs at cold temps. As 0W20 is a far thinner oil than 5W-20, it is more stable at cold temperature than the latter and flows smoothly through the critical engine parts.

5W-20 is a comparatively thicker viscosity oil and is better for a normal operating temperature range of -22°F to 68°F. 

B. Hot Viscosity 

Both oils act as an SAE 20 weight oil at warmer temperature settings. They provide decent fuel consumption, resulting in better fuel economy while lubricating all your critical engine parts.

In terms of their operating temperature range, both these grades operate well up to 68 °F. They are resistant to problems like oil burning and excessive oil consumption under high oil pressure and warmer temperature conditions. 

C. Performance

Both 0W-20 and 5W-20 are thinner oil grades that perform best in low temperature winter climates. 

0W-20 oil grade (due to its lower viscosity) is better with cold starts. It also prevents problems like sludge buildup, engine wear, varnish deposits, and low oil pressure. You can expect faster oil circulation with 0W-20 and a smoother flow.

So if you’re going to be driving a lot in below-freezing temperature climates and rarely drive in warmer temperature climates, 0W-20 oil grade would be ideal for you.

On the other hand, 5W-20 has a higher viscosity and performs slightly better in seasonal climates. It’s a slightly thicker oil and is more resistant to oil thinning at hotter temperatures.

Note: Some cars can take both 0W-20 and 5W-20 oil. But before you switch to a different viscosity grade, speak to your mechanic about the recommended oil for your car.

D. Fuel Economy 

Both 0W-20 oil and 5W-20 oil perform more or less the same in terms of their mileage and fuel economy.

0W-20 oil may give you slightly better fuel efficiency and fewer carbon emissions due to its thinner oil flow and low viscosity. 

But it also depends on whether you’re using a conventional, synthetic blend, or fully synthetic motor oil. Full synthetic 0W-20 and 5W-20 motor oil will give maximum fuel efficiency and better fuel economy.

E. Pricing

0W-20 oil usually tends to be slightly more expensive than 5W-20 oil. This is because (being a full or semi synthetic oil) it is more stable than the latter. 

The price of your engine oil also varies from supplier to supplier. Be sure to check with your mechanic to find the most affordable option for your car! 

Keeping these in mind, what are some things you need to know about these multigrade oils? 

4 FAQs About 0W-20 Vs 5W-20 Oil 

Here are some common queries about 0W-20 vs 5W-20 oil and their answers. 

1. Can I Use 0W-20 Instead Of 5W-20?

0W-20 is a thin oil viscosity grade that is typically used in cold temps. It is typically recommended for diesel and gasoline engines for cold starts and lower oil consumption. 

5W-20 has a similar viscosity level to 0W-20, also suited to low temperature climates, but has a slightly thicker oil viscosity than the latter.

Alternating between the two may not cause any immediate damage, but it will severely affect your oil change interval length and overall engine performance over time. 

So unless you have to, you shouldn’t switch to a different viscosity than the recommended oil by your car manufacturer.  

2. Can I Mix 0W-20 And 5W-20 Oil?

It is generally recommended not to mix any two different viscosity grade oils. 

For one thing, SAE 0W oil is always synthetic. 5W-20 may be a synthetic, synthetic blend, or even conventional oil. And even if both your oils are fully synthetic, mixing the two may affect your car’s fuel consumption and fuel efficiency. 

It is also possible that your 0W-20 and 5W-20 oils contain different additives like viscosity modifiers and corrosion inhibitors that are not compatible with each other. It’s, therefore, best to stay away from mixing or interchanging them.

3. Are 0W-20 And 5W-20 Available As Synthetic Oil?

0W SAE oils always contain synthetic or semi-synthetic base oils and additives. Being a lower viscosity oil, these need to be highly reliable under freezing temperature settings. 

Conventional oil can be unpredictable and break down pretty easily. So, 0W-20 oil usually contains semi-synthetic or fully synthetic base oil and additives to ensure it’ll flow in cold temps. 

5W-20 (with a slightly higher viscosity level) is more versatile in oil types as it is also available as conventional oil. 

However, you’ll notice clear differences between the conventional and synthetic variants of this oil. 5W-20 synthetic motor oil is far better, with improved fuel efficiency and oil change interval.

4. What Happens If I Put The Wrong Oil In My Engine?

Adding the wrong oil viscosity to your engine may not cause any immediate damage, but it will lead to engine wear over time.

If you accidentally add the wrong oil to your car, you can simply drain it and get an oil change. 

Using a thin oil, or thicker oils than the one recommended can void your car’s warranty. It can also affect the car’s oil consumption and fuel efficiency. Not to mention potentially causing excessive engine wear and damage to your car parts. 

If you add a heavier oil like 20W-50 oil instead of the recommended 0W-20 or 5W-20, your engine may face extreme oil pressure issues due to the different oil viscosity level. Heavier oil grades in the wrong engine may damage critical engine parts. It can also cause increased fuel consumption.

Final Thoughts

0W-20 and 5W-20 are low temperature, lower viscosity oil grades that are quickly replacing others in popularity. This is due to their versatile operating temperature range and several benefits, including better fuel economy. 

However, before you decide to switch over, make sure the oil grade is appropriate for your car. Using the recommended oil viscosity is important for engine life. That, and routine maintenance and repair! 

Getting a regular oil change and keeping your car’s engine in good shape can save you hundreds in the long run. So why not try out RepairSmith for that?  

RepairSmith is a mobile car repair and maintenance solution with ASE-certified technicians who come to you. Contact us today for a competitive and upfront cost estimate!