0W20 vs. 5W20: What is the Difference?

If you are an amateur in car specifics, then figuring out the correct oil to use is not as easy as ABC. Chances are you have messed up when attempting to be your car’s mechanic.

However, an oil change is one of those DIY projects that even an amateur can master. The issue is figuring out the right oil to use. Keep reading to learn the pros of using 0w20 instead of 5w20 and vice versa depending on theclimatic conditions or region.

Differences between 0W20 and 5W20

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. Below are the differences based on several factors;

Viscosity in cold weather

An oil’s viscosity is the measurement of its resistance to flow. It also refers to the oil’s thickness at various temperature settings. For example, 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. 0W20 is a far thinner oil than 5W-20. It is more stable at cold temperatures 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.

Viscosity in hot weather

Both oils act as an SAE 20 weight oil at warmer temperature settings. As a result, 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. As a result, they are resistant to problems like oil burning and excessive oil consumption under high oil pressure and warmer temperature conditions.

Performance

Both 0W-20 and 5W-20 are thinner oil grades that perform best in low-temperature winter climates. However, 0W-20 oil grade (due to its lower viscosity) is better with cold starts.

It also prevents sludge buildup, engine wear, varnish deposits, and low oil pressure. In addition, 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. In addition, 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.

Car Fuel Economy

For 0w20 vs. 5w20 fuel economy, both oils perform more or less the same in terms of their mileage and fuel economy. However, 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.

Price of the oil

0W-20 oil usually tends to be slightly more expensive than 5W-20 oil. This is because full or semi-synthetic oil is more stable. The price of your engine oil also varies from supplier to supplier.

What Happens if You Mix 0W20 and 5W20?

0W-20 oil is always synthetic, while 5W-20 may be a synthetic, synthetic blend, or even conventional oil. Mixing the two may affect your car’s fuel consumption and fuel efficiency.

Additionally, 0W-20 and 5W-20 oils contain different additives like viscosity modifiers and corrosion inhibitors that are not compatible with each other. Therefore, it is best to stay away from mixing or interchanging them.

Note: While it is possible to mix both 0W20 and 5W20 engine oils if they are both fully synthetic, it is not advisable to mix them. This is because both 0W20 and 5W20 have almost the same properties when utilized in fair-weather temperatures. However, there’s a higher chance the blended will fail at the -35°C test.

Additionally, even if both oils are fully synthetic and compatible, another problem that you need to keep in mind is the blending factor. The 0W20 oil is very thin and will likely fail to blend well with 5W20 in severely cold temperatures, usually at or under -35°C.

Which oil should I use in winter? between 0W20 and 5W20

0W20 and 5W20 are winter-grade oils designed for cold weather. Both oils are very similar, except for their composition and the lowest temperature they can flow. While both are low-temperature grade motor oils, when weighing between 0w20 vs. 5w20 for winter, 0W20 is slightly better to use in extremely cold weather.

Which oil should I use in summer? between 0W20 and 5W20

0W20 motor oil (0W20 oil) is one of the low-temperature grades. It has been liquid engineered to flow as smoothly in sub-zero weather. And it will still act as an SAE 20 once the engine has achieved its full operating temperature.

This type of oil will still crank at -35°C/-31°F and immediately flow through engine oil. In addition, this oil provides lubrication to critical engine parts, making it easier for you to cold-start your engine during winter.

5W20 motor oil is another low-temperature grade typically recommended for winter use, with a 10W-30 as an alternative for higher temperatures. This oil type is common because it provides the best fuel economy, saves fuel consumption, and has fewer exhaust emissions.

Both 0W20 and 5W20 are low viscosity and high-quality synthetic grades to optimize fuel economy massively. Furthermore, their properties are the same when used in fair-weather temperatures. In conclusion, regarding the 0w20 vs. 5w20 summer use debate,  there is little to no difference between the two versions when used in cold conditions.

When to Use 0W20 vs. 5W20

Below are some considerations when deciding to use either of the two oils:

Geographical Location

It is crucial to consider where you use the vehicle as both 0W20 and 5W20 motor oils fall within almost the same temperature spectrum. For example, 0W-20 synthetic oil’s range is between -40°C to 20°C while a 5W20 (5W20 synthetic oil) is from -35°C to 20°C. Knowing these details means two things:

It is better to use 0W20 oil if you live in very cold temperatures, such as Alaska or Maine.

You cannot use either 0W20 or 5W20 in areas where temperatures exceed 20°C/68°F, like Florida.

Your Owner’s Manual recommendation

Referring to your owner’s manual is quite simple yet often overlooked. Always check your owner’s manual to see the recommended viscosity of the motor oil you need to use. If both 0W20 and 5W20 variants are on the list, use them alternately without hesitation, depending on weather conditions.

Viscosity

The smaller the number, the better the motor oil will flow. For example, a 0W20 will be more fluid than a 5W20 at startup temperatures but will perform the same way at standard engine operating temperatures. Remember, engine oils naturally thicken as they cool down and thin as they are heated.

Quality Testing

Choose any oil brand with the right viscosity grade that displays the starburst symbol and the API donut. The starburst symbol shows that the oil has passed the tests listed for SL service. The API donut means that the American Petroleum Institute tested your motor oil and met the current SL service rating.

Manufacturer Requirements

Customarily, the machine designer would recommend a motor oil with high viscosity and heavy honey if your vehicle is heavily loaded. But if it runs very fast, a lubricant that can get out of the way and back just as quickly is more suitable.

Fuel Economy

Although 5W20 and 0W20 (0W20 synthetic oil) can be used at 20°C/68°F, 0W20 is thinner than 5W20 with cold engine temperatures, especially during the first few minutes after you start your car. New cars specify it because it gives the car a better fuel economy than the 5W20. The 0W20 variant also meets the demands of a turbo-diesel engine.

Check this too: How To Fix Low Oil Pressure At Idle

Best oil for summer 0W20 vs. 5W20

0W20 is a far thinner oil than 5W-20. It is more stable at cold temperatures 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.