Can I Use 10w30 Instead Of 5w20?

The motor oil greases the metal parts in the engine so that they don’t rub together and create friction and downgrade. Plus, the lubrication also preserves coolness in the engine. It closes the gaps between the piston and cylinder and also protects and coats the engine parts from acid, sludge water, and other corrosion and rust-creating elements. Motor oil also cleans acids and silicon oxide from engine components. That’s why it is vital to know about oil viscosity for the well-being of your car. So, it is common for someone to wonder, can I use 10w30 instead of 5w20?

If that question has crossed your mind as well, then this is where you can get the answer. Keep reading to find out what 10w30 and 5w20 are and learn more regarding oil viscosity.

What is oil viscosity?

what is oil viscosity

The term “Viscosity” is used for explaining the thickness of oil as well as its aversion to flow. The higher the viscosity number of oil, the thicker the oil is. The design of the older engines had looser tolerances, which allows oils like 10w30 to be used commonly as an OE-recommended oil during and before the 90s.

Better technology is being used for making modern-day engines, which equips them with higher tolerances. This means a thinner oil is required for properly lubricating the engine’s bearings and circulating quicker and freer throughout the engine. Also, using thinner oil will offer you the pleasure of using reduced oil in your car, but it isn’t always applicable. 

While thicker oil will typically stick to the engine parts easily, thinner oil moves faster and will get to the components of the engine quicker. However, the former also provides better greasing if there is a decrease in engine tolerance or in tough applications such as racing or off-road engines.

Viscosity determines how the oil of an engine will react to changes in temperature, speed, and pressure. Another essential factor to note is one must stick to the manufacturer’s recommended oil viscosity.

Related oil: best oil for Subaru WRX

What do the numbers mean in oil viscosity?

The digits 5, as well as 10, refer to the oil’s viscosity at lower temperatures. So, if you are wondering “can I use 10w30 instead of 5w20”, then understand that the 5w20 is thinner and will circulate faster. Also, during ignition, it will move better through bearing tolerance in cooler or winter climates.

The letter “w” after 5 and 10 represents the viscosities of oils in colder temperatures or winter. The test of winter number viscosity is done at 0° Fahrenheit. In comparison, 30 means the viscosity at higher-level temperature. At elevated temperatures, the oil is thicker, which enables it to stick to the engine’s metal components and keep them safe as they operate. The test of this number is done at 212° Fahrenheit instead of 0°.

The viscosity number is determined by the SE or the society of Automotive Engineers. For instance, they determine how fast the movement of the oil will be through a certain-sized tube.

When comparing 5w20 vs 5w30, the 20 denotes an oil with lower viscosity, which, at higher temperatures, is thinner. This allows the oil to reach engine components quickly and easily. Therefore, because of viscosity, 5w20 is a thinner oil at operational temperatures, while 5w30 is thicker in that phase.

Many automobile manufacturers now creating engines that run on 5w20 oil. So, instead of using 5w30, it is now very essential to stick to the set viscosity.

Why do some oils have only one number?

Oils were traditionally made in only one grade such as SAE 30. At that time, seasonal change of oil was required. Lower viscosity oil was used in the winter and a higher viscosity in the summer. Later, the formulation of thickening agents was made and multi-grade oils became popular.

What is the 10w30?

10w30 engine oil

A multi-grade engine, the 10w30 oil is best for heavy-duty engines due to the fact that it is capable of resisting high temperatures for an extended period and that so without compromising on the engine’s performance.

The viscosity grade of this engine oil is 10 at low temperatures, whereas 30 at high temperatures. Low viscosity is maintained by the engine oil at low temperatures, meaning when the environment is cooler, it’s thin.

Key specifications of 10w30

The ACEA rating, API SN, and the grade of viscosity are some of the aspects that you should keep an eye on when it comes to the 10w30 engine oils. The American Petroleum Institute started a number of engine categories and the API SN is one of them. This type of motor oil ticks the full checklist of API SN. The requirement remarks that the piston must be protected by the engine from anything that could cause combustion.

The improved sludge control is also this oil’s feature, which means the motor will not accumulate any unwanted sludge or gel at high temperatures. The compatibility of 10w30 motor oils also goes with the seal as well as after treatment.

Having an ACEA A3/B3 or A3/B4 rating is a must for 10w30 motor oil as per the ACEA or European Automobile Manufacturers Association. The association assigns oil sequences to several specifications of the engine oils.

10w30 motor oil advantages

There are a number of unique features as well as benefits in 10w30. The 10w30 engine oil forms an unceasing layer over the engine’s different components, which decreases friction among them. This maintains the preferred engine temperature and also reduces the deterioration the engine endures in-between start and stop operation.

10w30 also provides protection to the engine’s section from corrosion. Plus, it increases the life expectancy of the engine as well. The user also experiences noiseless as well as smooth clutch and gear operation at all times. At high temperatures, the engine oil maintains its viscosities effortlessly.

It is the ideal choice for an engine that runs on advanced fuels like biofuel and biodiesel. While you can use 10w30 for cold climates, it is ideal for warm weather.

What is 5w20?

5w20 engine oil

Used in automobiles, the 5w20 is a multi-grade viscose oil. It has a 5 viscosity grade at cold temperatures. And the grade leaps to 20 in high temperatures.

Key specifications of 5w20

5w20, like the 10w30 matches all the API SN as well as ACEA specifications, which differ according to oil brands. The Mercedes Benz requirements also approve this oil, which assigns a certain grade to motor oil. Your brand choice will determine the grade of oil. Volkswagen, Porsche, and Ford also approved the 5w20.

5w20 motor oil advantages

There are a different number of features that enables the oil to be prominent from the rest. Just as its competitors such as 10w30, the 5w20 motor oil also forms an unceasing coating over the engine’s components to reduce abrasion between them. Also, it protects the engine from rusting and decreases deterioration.

Moreover, 5w20 oil can enhance the lifespan of the engine. The thermal stability is much better in it, which allows the properties of this oil to stay unaffected even with a temperature variation. The creation of motor oil maximizes fuel economy. And greasing the engine also demands a bit of engine oil.

The 5w20 motor oil is well-suited for automotive light-duty petrol and light-duty diesel engines, and also gasoline engines. At lower temperatures, it gives a nice flow and that is why it is an ideal preference for lower temperature climates.

What are the differences between 5w20 vs10w30

difference between 5w20 and 10w30

When wondering “can I use 10w30 instead of 5w20” you need to know the differences between the two in order to understand the possible alteration if the oils are swapped.

Both 5w20, as well as 10w30, are the same engine oils. However, their viscosity creates a difference between them. Both of them are multi-grade motor oils and they work fine in both low and high temperatures. Below is a comprehensive discussion regarding the differences between both engine oils.

Different meaning

In both 5w20 and 10w30, the “W” refers to winter. Due to the oil’s lower viscosity at low temperatures, these engine oils feature a higher resistance to air flow. In comparison, however, the 5w20 is thinner. Therefore, the inner parts of the engine will receive better and quicker protection from 5w20 than 10w30.


The SAE ratings on both the 5w20 and 10w30 are similar, which means their performance will be similar at high or functioning temperatures. As you have seen above, the 30 on the 10w30 refers to oil’s viscosity at higher temperatures. In cold weather, the 10w30 has a tendency to get thicker, which makes the 5w20 a more ideal option for such environments.

Best use

Before choosing engine oil, you need to consider the environment of the location where you will use the vehicle. Even though both of the discussed engine oils are multi-grade, the ideal choice for low-temperature use is the 5w20 as it thins enough in such area. This means, compared to 10w30, its performance is better in the winter. Alternatively, in summer or high temperatures, the 10w30 flows effectively.


When it comes to lubrication, 5w20 outperforms 10w30. So, it is ideal for private cars, as well as light-duty diesel as well as petrol engines. On the other hand, the 10w30 is the ideal choice for commercial cars and also ones that carry heavy loads.

Can you mix 5w20 and 10w30?

Typically, when two oils of different weights or viscosity are mixed, it is not likely to cause any issue for the engine because both oils will do the job they are supposed to do, which is lubricating the engine. However, the belief that mixing oil enhances the performance of a vehicle’s engine is a myth. 

Because the additives of the oil are there for a number of reasons. These enhancers have some incompatibility, which would prevent your engine from receiving the whole advantages of mixed oil as against untampered, pure oils.

However, when it comes to combining 5w20 and 10w30, the effect of the oils will be governed by the vehicle. Which oil is your vehicle built to run on? Not following the manufacturer’s recommendations and mixing 5w20 and 10w30 will not cause any harm to your engine. But, there are claims from a few drivers that combining two straight-weight oils or multi-grade oils is safer than mixing straight-weight oils with multi-grade oils.

The 5w20 easily flows in cold or low temperatures and always keeps the components of the engine lubricated. In comparison, while the 10w30 flows in cold or low temperatures, the flow speed will be lesser than that of 5w20.

Although there are different kinds of motor oils available in the market, the 5w20 and 10w30 are the most popular options. You are not likely to notice any significant issue if you add 5w20 to a vehicle that has been running on 10w30.

In the winter seasons, the 5w20 in your vehicle’s engine will make it run smoothly because of its low viscosity grade. One thing you also need to know is that it is quite impossible to blend or mix oils without a difficult, long process. 

Mixing 5w20 with 10w30

When you mix 5w20 with 10w30 and pour the mixture into the engine, the oils won’t blend, they will still stay separate. So, you are just going to get some quarts of 10w30 and 5w20. They will not become a single oil as you might have hoped. That said, there is no issue in using two different oils in an engine. However, as a result of your mixing, the frequency of oil changes will reduce.

If the engine of your vehicle is made to operate on lighter oils, then using thicker oil in it may cause an increase in fuel consumption. This is because the engine tends to utilize more energy to use thicker oil, which reduces fuel efficiency.

Can you use 10w30 instead of 5w20?

The performance of any engine is greatly impacted by the choice of oil. Certain engine components are built to function better with a particular oil. So, can you use 10w30 instead of 5w20? Let’s find out.

External temperature

A lower number prior to the “W”, means the viscosity of the oil is thinner. It is easy to light thinner oils even under negative temperatures. Therefore, if you are going to drive your vehicle in a below-zero environment, then select 5w20 oils. Similarly, the combustion of 10w30 oil will take hours. So, when selecting the oil for your vehicle, you should keep the weather in mind.

Effect on engine components

Parts such as the rod as well as the main bearing help to endure the rotating shaft’s pressure. Generally, these parts work well with thicker oil because it leads to a harsher coating. The thinner oil, 5w20, won’t be able to support the component’s weight and will eventually wear out. On the other hand, components such as cooling nozzles can work greatly with thinner oils.

If the nozzles are supplied with thicker oils, they will undergo a reduced flow. In such situations, it is highly recommended to use and follow effective maintenance tips or just contact a mechanic.

Engine and fuel economy

If you use 10w30 instead of 5w20, maybe a few changes will present themselves, especially if it is an old engine and is on the brink of wearing out. Moreover, the thinner oil’s ability to combust faster is another one of the advantages. Due to this, pumping the fuel won’t take much effort from the engine, which reduces the fuel economy. On the contrary, because of uneven circulation of oil in the piston region, the engine’s lifespan might reduce. 

Which viscosity is better?

The manufacturers recommend engine oil in the owner’s manual, using that is the best method for having the engine function efficiently, protecting it from unwanted issues, and getting good mileage. You should note that numerous owner manuals recommend an array of oils. Thus, the answer mainly depends on your location and the climate. So, if your manual recommends a specific weight, then use that.


1. Which is thicker between 10w30 and 5w30? 

In lower temperatures, 10w30 has a higher viscosity, which makes it thicker than 5w30.

2. Which is finer between 5w30 and 10w30?

Both 10w30, as well as 5w30, are great engine oils. In order to get optimal operation, it is important to comprehend how they work in a certain environment. The 5w30 is great for all seasons and provides the utmost protection in summer as well as winter. You will also get a good level of fuel efficiency from this oil because it generates minimal grind on moving parts as well as the bearing of the engine.
On the other hand, engines that are older work great with 10w30 oils because their thickness gives an extra seal.

3. Can I switch to 10w30 from 5w20?

Between the two oil, the only distinguishable difference is the cold flowability. In cold temperatures, 5w20 engine oil will move quickly compared to 10w30 oil. You should go with the oil weight recommended by the manufacturer as this will help you get optimal performance from the vehicle.

Final words

10w30 is heavier and thicker and it protects older engines. 5w20 is a multi-grade, thinner oil and the ideal choice for faster ignition in colder temperatures. In order to keep your vehicle in optimal condition, you should feed it only certain motor oils recommended by the manufacturers.

So, if the question, “can I use 10w30 instead of 5w20” raises in your head, you now know the correct answer.