Updated at: 25-07-2022 - By: Lucas

The number of engine oil viscosity options accessible to consumers grows each year with the launch of new vehicles. Most car owners, on the other hand, do not require the whole range of oil weights given by manufacturers.

One of the most frequently asked questions is how to choose between 0w40 and 0w20. If you’re a car owner, the following 10 distinctions between 0w40 and 0w20 motor oils will help you make a better choice.

0w20 engine oil is a popular choice. Find out why so many people prefer this kind of oil above others in the following paragraphs.

What Is 0W20 Oil?

0w20 vs 0w40 (3)

Blended with mineral and synthetic oils, 0w20 oil is developed to provide exceptional lubrication and protection for the engine. Even in subzero temperatures, 0w20 oil will keep your engine running smoothly and effectively.

0W20 And Other Oils

Although 0w20 engine oil’s viscosity can be compared to other types of oil, it is unique in that it delivers better high temperature stability, shear resistance, and oxidation resistance than other models.

For roller cams and flat tappet cams, 0w20 is incompatible. Pennzoil, Mobil 1, Royal Purple, and Amsoil are some of the best-known brands that produce 0w20 oil.

0W20 Use

High-end automobiles benefit most from the usage of this particular lubricant. Certain Lexus and Audi cars, for example, require 0w20 oil to work at their best. In colder climates, 0w20 engine oil’s viscosity rating means it won’t perform as well.

What is 0w40 oil?

0w20 vs 0w40 (2)

It is a specific weight of oil, which is named for its viscosity rating under low temperatures (the 0), the lower end of the range for this viscosity (the w that stands for winter), and the highest end of the range for this viscosity (the n) (the 40 which means the flow at high temperature).

The oil’s ability to resist flow is measured by its viscosity. This means that less resistance is required for water to flow and that it can drain faster from regions where it isn’t needed (such as bearings).

Higher numbers (such 10w40) indicate more resistance to flow, resulting in a slower drain rate. As a result of the lower viscosity, the oil can reach the bearings more quickly during cold starts.

Higher viscosity oil is beneficial for high temperature operation because it drains slower in certain locations.

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Oil Viscosity Grades

Viscosity is used to assign grades to motor oil. Car manufacturers commonly employ 0w20, 5w20, and 10w30 grades. When compared to other oils, this suggests the oil is light.

Centistokes or stokes are the conventional units of measurement for this factor, and this number represents its standard value.

Ten differences between 0w40 and 0w20 engine oils

1. Top-end oil pressure

Since it has a higher maximum oil pressure at 0w20, this oil is better suited to lubricating the engine at higher speeds and RPM. 0w40 has a lower oil pressure at the top end, which provides better protection at low speeds.

2. Cold weather viscosity

0w20 has a lower cold weather viscosity, which indicates that it flows more easily when the temperature drops below zero degrees Celsius. When it’s cooler outside, having an easier time starting your car is a plus.

A thicker viscosity in cold temperatures means that 0w40 is better at safeguarding your engine over long periods of idling in the winter.

3. High-temperature viscosity

Higher high temperature viscosity of 0w20 offers better protection of your engine from heat and friction in hot weather and high running temperatures..

Because of its decreased high-temperature viscosity, 0w40 is easier to work with and results in less engine wear and tear.

4. Thermal stability

To put it another way, 0w20 has better thermal stability, which means it won’t deteriorate (thin out), thicken more slowly, or create deposits when used in hot environments.

In high temperatures, 0w40’s lower thermal stability can lead to oil pressure loss and degradation (thickening).

Metal particles and sludge are more prone to build up when exposed to high engine temperatures for an extended period of time.

5. Pumpability

Because 0w20 has a higher pumpability than 0w40, it is less prone to produce problems like clogged filters, oil passages, and lower oil pressure.

Since a result, the oil is being fed to the engine in bigger quantities for better lubrication, as it flows more easily through the engine oil pump.

Lower pumpability implies 0w40 is more prone to clogging of filters, oil passages, and reduced oil pressure. 0w40

6. Viscosity index

Because of its higher viscosity index, 0w20 is more resistant to viscosity breakdown when working at high temperatures.

Because of this, it is better able to withstand prolonged exposure to high temperatures than 0w40. When heated to a higher temperature, 0w40’s viscosity index drops, indicating that it is more susceptible to viscosity breakdown.

So, when exposed to high operating temperatures for extended durations, it may not give the same level of protection and performance as 0w20.

7. Cold weather performance

If you live in a climate where cold starts are critical, 0w20 is the best choice. When compared to 0w40, it can make starting your engine easier in colder temperatures.

Warmer climates, where cold startup isn’t as crucial, benefit more from 0w40’s cold weather performance.

8. Suitable for modern engines

To utilize 0w20 in modern gasoline-powered passenger automobiles, the manufacturer’s technical advice must enable it, including direct injection (DI) and turbocharged versions (T/C).

Modern gasoline engines, such as direct injection and turbocharged models, can run on 0w40 if the owner’s handbook permits it to be done.

9. High-performance engines

When used in high-performance turbocharged gasoline engines in passenger cars, 0w20 is a high-performance oil that can give improved protection. Vehicles equipped with high-output turbocharged gasoline engines are not advised to use 0w40 oil.

10. Fuel economy benefits

It’s possible that 0w20 offers better fuel economy than 0w40, but it all depends on your driving style, your engine, and the normal operating temperature range of your vehicle. Consult your vehicle’s owner’s manual to find out what kind of engine oil your vehicle requires.

Can 0w20 be used in an older engine?

The additive package (or formula) in 0w20 motor oil is specifically developed to safeguard your engine from severe stress and increasing temperatures, which makes it an excellent choice for heavy mileage autos. Newer engines should have 0w20 oil added at the manufacturer’s recommendation.

Can 0w20 cause harm to the older engine?

Drivers frequently ask this question. For some people, the idea of using a lower viscosity grade than what their car manufacturer recommends can be frightening.

Older engines may benefit from lighter oils, but it’s best not to use 0w20 unless the manufacturer specifically recommends it because it can damage the engine.

Can 0w40 be used in a newer engine?

The performance is similar to that of 5w30 or 10w30, however because of its smaller weight, it will heat up more quickly. Engine life may be extended due to the earlier lubrication of the engine.

Can 0w40 cause any harm to the engine?

Temperatures below 20 degrees Fahrenheit (29 degrees Celsius) can cause damage to the engine if 0w40 is utilized.

Colder temperatures will cause this oil to thin out even more because of its low viscosity. In addition, because of its lower viscosity index than other oils, it may not operate as well in cold temperatures.

Can you mix 0w20 and 0W40?

Oil viscosities can be dangerous, however the best option is to use only one grade of oil. There may be difficulties with your engine that are not immediately apparent if you use different grades of oil.

Bottom line

What’s the verdict?

For most automobiles, 0w40 is the best engine oil. Using 0w20 oil is the best option if your vehicle is newer or requires thinner lubricants. It’s always best to go with 0w40 if you don’t know what kind of oil your car requires.