5w30 vs 10w30, 10w40, 0w30 Engine Oil Viscosity: Which one is Better?

Which engine oil viscosity is better? When it comes to picking the right engine oil for your car engine, there are many choices to pick from. Due to the variety, choosing the one that is right for your car might be a daunting task. While there is a lot of information about the various choices of oils, the first step that you need to consider is by looking in the manual.

In your car owner manual, there is a list of recommended oil weight, whether it is a standard 5w30 vs 10w40 ,10w30, 0w30 engine oil viscosity or any other. You will have to choose an oil with recommended weight from a brand which displays a symbol of starburst that confirms it has been tested by API.

xWy Oils: What Do The Numbers Mean

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The numbers represent the viscosity of the oil. 0w30, 10w40, 10w30. When you are out choosing which oil to use on your car, use what the manufacturer recommends for your specific type of car.

There is a reason as to why the manufacturer has recommended that viscosity with the main reason being that, there is a way the engine of your car is built and it requires that specific viscosity.

In case you decide to place a heavier oil in the engine than what is required, the engine will not get the oil quantity it requires nor in the particular places where it is needed. The engine is also dragged down and thus end up causing additional stress and wear on the internal engine parts which are running the oil pump.

If the relief pump gets a lot of pressure, some of the oils will be bypassed and it will not be used for engine lubrication. None of the above is good for the engine. And in case you place a lower viscosity oil in your car engine, it will cause the engine to lack the needed pressure to allow the oil to all the places it needs to be.

In both scenarios, there is an increase in the wear and tear of the parts. At first, you might not be able to see it, but it affects the longevity of the engine. Always use the oils specified by the car manufacturer manual based on temperature.

More details: https://www.rymax-lubricants.com/blog/what-does-5w-30-actually-mean/

See more : Best penetrating oil for seized engine – Top 5 Best


Viscosity refers to the resistance to flow of a liquid. When it comes to motor oil, it is rated at zero degrees Fahrenheit which are represented by the digit which precedes W, that stands for winter at 212 degrees which is well represented by the second number in the designation of viscosity. When it heats, motor oil thins and when it cools, it thickens. (source)

So when you have the correct additives, it will help in ensuring that the thinning is eliminated, oil is able to be rated for one viscosity when hot, another when cold. The more it resists in thinning, the higher the second number will be, for example, 5w 30 vs 10w40. Within reason, oils which are thicker tend to seal much better and always maintain a lubrication film that is better between the parts which are moving.

Source: https://en.wikipedia.org/wiki/Viscosity

When the temperature is low, oil needs to be resistant when it comes to thickening to enable it to flow more easily on the various moving parts of your engine. When the oil is too thick, there will be a lot of energy required by your engine in order to turn the crankshaft which is normally partly submerged in an oil bath.

When the thickness is excess, it makes it harder for the engine to start, thereby reducing the fuel economy. In winter a 5W oil is the best to use. However, when using synthetic oils, they are formulated in such a way that they are able to flow more easily when it is cold, and thus, pass the tests which meet the 0W rating.

High Mileage Oil

High mileage oil is formulated for high mileage vehicles, vehicles which last longer. When your car or SUV/light truck is older and has more mileage, it is possible to notice a few oil stains on the garage floor. When you see that, there will be a need to add quart more often than when the car was still new.

There is a possibility that the crankshaft seals have become harder and thus, lost their flexibility and that is what makes them leak and with time, may crack. The mileage of oils which are high are made in such a way that, they have a seal conditioners which are able to pass through the seal pores tolmake sure that their shape is restored and flexibility is increased.

In certain cases, the rubber seals are designed to be able to swell to stop the leakage. The high mileage oils also have higher viscosities and more viscosity index improvers. This, in the long run, results in the seal piston to cylinder clearance to be better and thus no squeezing out as from the larger engine bearing clearances.

They have a high dose of antiwear additives which help in slowing the wear process. So if your vehicle is older, the above features may mean a lot to you than what you might get from a full synthetic, at an affordable price.

How Oil is Graded

Oil is not just oil. When you go to purchase, you will get a huge range of options available at various prices. When you look at the bottle closely, the specifications are random letters and numbers, which are similar to those that are priced differently. There are three core types of oil available in the market: synthetic, semi-synthetic, and mineral.(source)

  • Semi-synthetic: This is a blend of mineral and synthetic oils. It is in the market to carter for those who want synthetic oil yet they cannot afford its high price.
  • Synthetic: It is the most expensive oil, but for a reason. Scientists have engineered it to work on a variety of conditions and temperatures, while at the same time, reducing the engine drag, which in the process, help in reducing consumption of oil. When used, it actively cleans the internals of the engine as it is pumped around.
  • Mineral: It is the cheapest and it can be regarded as a constituent of crude oil, which is produced after it is refined. There are very few car companies which recommend this particular oil as it does not come with the engine cleaning detergent which are required for cars today and it has a limited range of temperature operation. It is okay to use on old engines that have a tolerance which is less extreme and are used in a mild climate without freezing or the weather that is really hot.

What is a 5w30 oil?

A 5w30 oil is an oil that has a weight of 5 pounds per gallon at 30 degrees Celsius. It is lighter than a 10w40 oil, which has a weight of 10 pounds per gallon at 30 degrees Celsius.

What are the benefits of using a 5w30 oil?

There are several benefits to using a 5w30 oil in your vehicle. One benefit is that it helps to improve fuel economy. It also helps to protect your engine against wear and tear, and it can help to reduce emissions.

What are the drawbacks of using a 5w30 oil?

The only drawback of using a 5w30 oil is that it may not be as durable as heavier oils. This means that it may not last as long in your engine.

Which oil should I use in my vehicle?

The best oil to use in your vehicle depends on the make and model of your vehicle, and the climate you live in. If you are not sure which oil to use, consult your vehicle’s owner’s manual or talk to a trusted mechanic.

Which Oil Should Vehicle Owners Use?

#1. 5w30 vs 10w30

“]What is the Difference?

The difference between 10w30 and 5w30 is in the thickness in cold temperatures with 5w30 being more thinner than 10w30. That is why it will be best if you used 5w30 instead of the 10w30 if your vehicle operates in climates that are cold.

The first digits 5 and 10 refers to the measurement of how easy it is to pour the oil when at low temperature. When the number is lower, it means that the oil will be thin in these conditions.

Having a 0 pour is easier than having a 5, and with a 5 being easier than a 10 and so on. When the oil has a lower viscosity, which refers to the first number being lower, it will be able to reach and protect the engine inner components faster than the one that has a higher viscosity.

Both these oils have a 30 as the second digit. The number 30, in this case, refers to the oil thickness once it reaches high or operating temperatures. When the viscosity is thicker or higher, the oil with then has to adhere to the components that are mechanical in a better way when they are subjected to high stress and pressure and they will be able to resist higher temperatures before they thin out beyond the viscosity for working. Working viscosity refers to the viscosity which after that, it cannot be able to provide enough protection for your engine.

When should I use 5w30 vs 10w30

The two oils 10w30 and 5w30 are the same, with the only difference coming in when it comes to the cold flowability. A 5w30 is best for a vehicle like a Silverado or a Turbo, for a lawn mower, snowblower. A car like a C5 Corvette will also function well on 5w30. It is faster than a 10w30 when it comes to flow movement during cold startups. When at the operating temperature, the 30 shows that, both have the same viscosity and will protect and flow in the same way.

If you are going to use the oil during winter time, in cold weather and where you live gets cold like in California, it is advisable that you use the 5w30 oil as it is good in winter weather. If you are going to use the vehicle during summer in Texas, then it is advisable that you use 10w30. In the case where you live is in a tropical area where the temperatures are always high without getting too near freezing, you can decide to use a higher viscosity of 15w40.

Before you decide on which one to use, you will need to consult your manufacturers manual and ensure that you use what is specified there. This is because, whatever the manual says, it is what is going to keep your engine to have the best protection and give it maximum fuel economy. You will need to consider synthetic oil vs mineral and semi-synthetic because, even though it cost more, it is more quality. Purchase it from reputable companies such as Amsoil Inc.

When you use oil which has a viscosity that is too high is likely going to make it have high oil temperatures and the drag on the engine will go up. When an oil which has a low viscosity than that specified by the manufacturer is used, it is going to cause the oil to fly on the internal components when in motion, and in the process, results in metal to metal contact which will cause high wear and tear of the engine.

Most car manufacturers will ensure that they specify the range of oils which you can use in your car and thus, you will be at liberty to choose the viscosity you like but within the range. If you own a Honda Civic and the 5w20 specified by the manual is not available, the manufacturer advice that, you can go ahead and use the 5w30 oil without having to worry because it is also good for the engine of this particular car.

The Pennzoil car engine can use both the 5w30 and 10w30 without a blink. The WRX seems to work well with the 5w30. The Royal purple 31130 engine will use the 10w30 with the 11744 series using the 5w30 oil. If you own a generator, then the best engine oil will depend on the generator type: for a Honda 08207, 10w30 engine oil will be ideal.

#2. 5w30 vs 0w30


What is the Difference?

If you are operating in an area with a low temperature, with cold surroundings, then you will require a very low viscosity grade. What this means is that the 0w30 will be more appropriate than the 5w30. But at a 100 degrees Celsius, both 5w30 and 0w30 are at the same viscosity. When the temperatures go down, then the 0w30 is more preferable as it has the least viscosity.

The w in between the two digits stands for winter and it is an indication that the oil in question has a different viscosity or different characters inflow based on the temperature. The weight rating of 5w30 refers to the fact that, when it is on a cold startup, even at the lowest temperatures possible, the oil will flow like a 0 oil weight.

The 0w30 rating means that, when it is on a cold startup, even at the lowest temperatures possible, the oil will flow like a 0 weight oil. But for both, once they are warmed up to around 210 degrees, they are going to function as a 30 weight oil. This will be possible through the inclusion in the mixture of certain additives.

Why want a thinner oil which acts like a thicker oil once it is warmed up? If you went ahead and used an oil weight of 30, the chances are, the lubricant is going to be too thick to get through the engine when you start it on a cold day meaning, it will fail to do the protection of crucial parts in the engine from damage.

At the same time, it will be risky to run an engine on a 0 oil rating throughout due to the fact that, it is going to be too thin to be able to keep the engine which is warm, safe. For both worlds, multigrade is what will work best: 5w30 or 0w30 depending on the manufacturer’s manual.

When should I use?

You will need to use the engine oil weight which is recommended by your manufacturer in the manual. Most manuals will recommend a range of oils which take into account how harsh the winter weather might be and whether you are going to put extra on your engine by hauling a heavy load or towing.

There is no one size that will fit all the vehicles and thus, the 0w30 or 5w30 will depend on your specific vehicle. Just ensure that you go through your manual and choose the right oil grade, which will match with how you drive in order to better protect your engine.

Ensure that the viscosity you are choosing for your car is going to extend the engine and thus, it needs to be high mileage. It should feature a blend of high-performance synthetic base oils which will deliver while protecting the engine. They should be able to reduce leaks and provide high-temperature protection. The oil pressure should be right

Most motorcycles would do well with a 5w30 oil. Jeep 4.0 would do well on a 5w30. Dirt bike will do well on a 0w30. Scooter 4T would best run on 0w30. Outboard, marine, Pennzoil, honda grom, lawn mower, liquid moly, perbedaan, Amsoil, ATV,aceite, Castrol magnatec, yamalube, generator, depending on the model, can either run on 0w30 or 5w30 or both. Mobil 1 is normally a recommendation by ExxonMobil for SAE 5w30 and 0W30.

#3. 5w30 vs 10w40


What is a 10w40 oil?

A 10w40 oil is an oil that has a weight of 10 pounds per gallon at 40 degrees Celsius. It is heavier than a 5w30 oil, which has a weight of 5 pounds per gallon at 30 degrees Celsius.

What are the benefits of using a 10w40 oil?

There are several benefits to using a 10w40 oil in your vehicle. One benefit is that it helps to improve fuel economy. It also helps to protect your engine against wear and tear, and it can help to reduce emissions.

What are the drawbacks of using a 10w40 oil?

The only drawback of using a 10w40 oil is that it may not be as durable as lighter oils. This means that it may not last as long in your engine.

Which oil should I use in my vehicle?

The best oil to use in your vehicle depends on the make and model of your vehicle, and the climate you live in. If you are not sure which oil to use, consult your vehicle’s owner’s manual or talk to a trusted mechanic.

Difference between 5w30 and 10w40?

Each moving part in an engine requires lubrication for it to minimize the wear and tear of all the surfaces which come into contact with each other. Apart from lubrication, the oils that you put in your engine does clean the engine, prevent corrosion, seal as well as cool the engine by ensuring that the heat is transferred away from the machine.

That is why it is important to use oils which are recommended for a particular machine or engine. There are a number of oils which are recommended in vehicles with 5w30 vs 10w40 being very common.

5w30 is a motor oil which is synthetic and has a viscosity of 5 when in low temperature and 30 when in high temperature which is normally at 100 degrees celsius. 10w40 refers to synthetic oils which have a viscosity of 10 when in low temperatures and a viscosity of 40 when in the high temperature of 100 degrees Celsius.

5w30 is less viscous while 10w40 is more viscous. The 5w30 has a viscosity of 30 at high temperature while a 10w40 has a 40 viscosity at high temperatures. What is then the difference between the two apart from the difference in viscosity?

The main difference between the 5w30 and 10w40 is the viscosity difference at different temperatures. The numbers of oil show the various viscosity at high and low temperatures. The first number 5 and 10, shows the viscosity of the oil at low temperature while the last digits, 30 and 40, show the viscosity of the oil at high temperatures.

The w in between stands for winter, meaning, the viscosity at which the oil will be able to flow when the car starts or at a temperature which is low. The one, 5w30, will be able to flow better when the temperatures are low than the 10w40. So at a lower temperature, the 5w30 oil will be the best to protect the engine. This is when the engine is in the winter season or when it is just starting.

When at high temperatures, the 5w30 oil becomes thinner than the 10w40 oil since 30 is lower as compared to 40. It is important to remember that, these numbers do not depict the actual viscosities of the oils when at extreme temperatures.

The 30 and 40 in the digits of the oil names describe the viscosity of the oil when the engine heats up and the oil comes to its maximum temperature while in operation. The warm viscosity will always be heavier due to the engine’s requirement of a higher viscosity oil, which will provide it with enough lubrication through the broad range of the engine temperature and cycle.

This means that the 10w40 will be able to hold onto the engine parts than the 5w30 at a higher temperature. It means that the 10w40 becomes thicker when the engine of the motor is running.

When should I use?

Motor vehicle manufacturers normally ensure that the fuel economy of the engine is high in order to be able to meet the government regulations and in the process, provide an edge against the rest in the marketplace. Thinner motor oils such as 5w30 will provide less friction to the engine which will then result in an increase in fuel economy. Car manufacturers manuals will always recommend such thinner oils for such a reason, but you should remember that it will come with an increase in engine wear and tear.

When the engine keeps on rotating with the cylinders moving in and out of the engine block, it creates wear and reduces the engine lifespan. The more the engine wears, the more the fit between the cylinders and the block loosens which then increases the wear and at the same time, decreases its usable life because the engine keeps on developing more gaps between the parts which are in motion. When you use a thicker oil such as 10w40, you will be able to provide the parts with more lubrication which will be able to compensate for the excess wear of the high mileage engines like those of BMW, Ford, Volvo, and Audi.

Many mechanics who are experienced will recommend you to shift to a velocity which is higher when it comes to motor oil as the engine becomes older in order to compensate for the imperfections.

#4. 10w30 vs 10w40


What is the Difference?

The 10w30 and 10w40 are the most common engine oils. Although the difference between the two is not much, it is still important to understand how they differ in terms of their viscosity and how each affects the oil change and fuel economy.

The shortest difference between the two is that the 10w40 is thicker than the 10w30 when in high temperatures. For you to understand the difference in depth, you will need to understand the basics in the parameters regarding engine oils

Viscosity is more than just a physics term and every auto owner understands what viscosity is all about. When you compare oil and water, oil is thicker than water meaning, when you pour water and oil at the same time, water will be able to fill much faster than the oil. That is what viscosity is all about: oil is more viscous than water. It has a higher viscosity than water.

Internal components of a vehicle including the engine of vehicles with high mileage require the oil in order to operate effectively and which in return, affects the fuel consumption. The oil which you use needs to be able to handle different fluctuations in temperatures. If your engine generates extreme heat, then the oil needs not to be too thick because, if so, then it will not flow smoothly internally.

The 10w30 and 10w40 both have the same starting number indicating that, during the winter, both oils will flow at the same viscosity in the low temperatures. When the number is lower, then it is much easier for the oil to stream during winter. It means that, compared to these two, if you get oil which starts with a 5, it will be the best for the cold season.

The w in between stands for winter and it is the one which determines that the first number in this case 10, is referred to when the temperature is in winter. The last number, 30 and 40, suggests how easy it will be for the oil to flow when the engine is at its optimal temperature or during the summer season. When this number is high, then the better the oil will be able to work in protecting the engine components during the extreme heat and pressure. Between the 10w30 and 10w40, it means that, during summer or extreme heat, you will need to go for the 10w40.

When should I use?

The best way to know which oil between 10w30 and 10w40 is suitable for your car is by checking your manual. There are always specifications from the manufacturer about which oil will work best with your type of vehicle engine.

The 10w30 engine oil will work well if you stay in regions which are colder, then this is the best oil to use. This is because, the heat from outside will not be much and thus, the only heat which will be affecting the engine will be the one which the engine will generate. But if you live in hotter regions, then 10w40 engine oil might just be the oils for you.

When you stay in areas which are hot, both the heat generated by the engine and the one from the sun will directly affect the engine. You have an option of using 10w30 engine oil, but the problem is that it will thin out faster and thus, damage the internal components of your engine. You will be better using the 10w40 as it will provide enough lubrication as well as protect the metal components.

The best way to find out which one to prefer is to check your manual or go ahead and call your authorized dealer. Remember that, the manufacturers tested and researched on the oils before deciding which one was the best for the engine. They have done tests for both hot and cold conditions and thus, if you follow what is in the manual guide, you will definitely get the best results.

Motorcycle engines, motorolie, aceite, huile moteur, Subaru, liqui moly, corsa c, and SAE engines can use the 10w30 or 10w40 or both, depending on the specifications by the manufacturers.


Q1: What is the difference between 5w30 and 10w30 engine oil viscosity?

Answer: The main difference between 5w30 and 10w30 engine oil viscosity is that 5w30 has a lower “cold” viscosity than 10w30. This means it will flow more quickly at colder temperatures, providing faster lubrication to critical engine parts when starting up. It also helps reduce wear during cold starts.

Q2: What about 0w30 vs 10w40?

Answer: The main difference between 0w30 and 10w40 engine oil viscosity is that 0w30 has a much lower “cold” viscosity than 10w40. This means that it will flow more quickly at colder temperatures, providing faster lubrication to critical engine parts when starting up and helping to reduce wear during cold starts. Additionally, 0w30 has a lower viscosity than 10w40 at high temperatures as well, which can help improve fuel economy by reducing the amount of energy needed to keep the oil moving through the engine.

Q3: What is the ideal engine oil viscosity for my car?

Answer: The best engine oil viscosity for your car depends on its make, model and year. Check your owner’s manual or consult a professional mechanic if you are unsure which grade of oil is recommended for your vehicle. Generally speaking, modern gasoline engines require an oil with a viscosity between 0w30 and 5w30. However, some diesel engines require the use of 10w40 or 15w40 oils.

Q4: When should I change my engine oil?

Answer: The recommended interval for changing your engine oil depends on your vehicle and driving habits. Generally speaking, you should change your oil every 3,000 to 5,000 miles or as specified in your owner’s manual. If you drive under more severe conditions such as frequent short-distance trips or towing heavy loads, the interval may be shorter. It is always best to check with a professional mechanic before determining the ideal engine oil change schedule for your car.

Q5: What are the benefits of using synthetic oil?

Answer: Synthetic oil provides several benefits including improved fuel economy, reduced engine wear and tear, improved lubrication in cold weather, and extended service life. Additionally, synthetic oils tend to be more resistant to oxidation and thermal breakdown than conventional oils. This means they can last longer under extreme heat and harsh driving conditions. It is important to note, however, that most synthetic oils should not be mixed with conventional oils as this can lead to problems with performance. It is best to consult a professional mechanic if you are considering switching from conventional to synthetic oil.


All the oils, the 5w30, 10w30, 10w40, and 0w30 have good weight for the engine when cold, low enough to get the oil moving through the engine faster. The weight of 30 when hot or at the engine’s optimum temperature is very common and ideal for many engines and most manufacturers recommend them. But in case you are having problems with the engine’s leaks and wear, you will find a few with a weight of 40 like the 10w40 engine oil, which is quite okay, especially in summer or those areas which are extremely hot as it will provide maximum protection when the engine is running, and slow escape through the engine leaks.

Read more: Have you ever seen a car with a milky oil cap?

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