Which is better 5w30 or 5w40. What oil is better to pour into the engine in winter?

Every motorist knows that the right choice motor oil The service life of the engine depends. Owners of modern cars need to think less about which substance is best to choose, because current manufacturers recommend products for the specific characteristics of different engines. It is more difficult for users of older vehicles to make a choice. To prevent the unit from presenting unpleasant surprises, for example, in winter, they need to be very responsible and attentive to the designations of the oils presented on the canisters. But the symbolism is so diverse, how to make right choice?

Main settings

If you decide to choose motor oil without professional help, then you need to familiarize yourself with the recommendations of the car manufacturer, taking into account the main differences between current lubricant products. An example would be semi-synthetic 5w40 and all-season oil 5w30. What is the difference between the presented products, which oil is better for your car model?

The main parameter of the oil is viscosity. According to the SAE (American Association of Automotive Engineers) classification, a double number in the classification, for example, 40, indicates the versatility of the product. It can be used at any time of the year.

Let's look at the notation using 5w40 as an example. In this case, the first value 5W describes the viscosity at low temperature. Semi-synthetics thicken more when the temperature drops. Consequently, it is more difficult for the pump to pump liquid. The second number indicates the high temperature of the liquid. The high viscosity of 5w40 promotes the formation of a durable film that provides good protection for the rubbing parts of the power plant. As for the numerical values, all liquids under consideration differ only in the temperature viscosity index.

Similarity of goods

Semi-synthetic ultra 5w40 is a high-quality product that provides good lubrication to all moving engine elements. The acceptable viscosity of the product allows you to start the engine even at low temperatures in winter. In hot weather, Shell 40 oil provides protection due to the formation of a good lubricating film.

Motor oil 5w30 is semi-synthetic with application class 5w. The product is distinguished by providing a durable film and offering good performance characteristics. Even taking into account that viscosity significantly affects the functioning of the engine, which is why you need to choose oil taking into account the manufacturer’s recommendations, this product is suitable for most modern vehicles. The letter “W” in the product name indicates that the oils can be used in cold weather.

Comparison of parameters

Whether it is synthetic or semi-synthetic, any product consists of base oils as well as thickening additives. The last elements are responsible for the necessary characteristics in winter and summer time. Lately, consumers are increasingly paying attention to all-season products, because they are much more effective and convenient. The viscosity class directly depends on the amount of additives. 5w40 oil, like 5w30, is capable of changing this characteristic by changing the shear rate. Accordingly, the lower it is, the higher the viscosity of Shell 40 oil. For example, the semi-synthetic index 5W30 varies from 9.3 to 12.6 mm2/s. For 40 the range is smaller - from 12.6 to 16.3 mm2/s.

When comparing 5w30 and 40 oils, it should be noted that they have different amounts of thickening additives. Therefore, determining which engine oil is best to use should be based on the viscosity characteristics, manufacturer’s recommendations, and weather conditions. In our case, when high temperatures the indicator is 30 and 40. The parameters determine how long the protective film will last on the parts of the unit in the summer. This is an important characteristic of semi-synthetics, because the film is responsible for premature wear power plants. If you use the wrong fluid, it is quite likely that the engine will stop unexpectedly during hot weather.

Considering that the higher the viscosity, the higher the resistance the pump will work towards lower flow. Consequently, the user will allow premature wear of the power plant as a whole. Due to oil starvation, parts will begin to fail and the engine will gradually break down. Accordingly, if 5w40 is recommended, but the engine is filled with semi-synthetic 30, then the oil film will not be strong enough and the oil will be too thin. Thus, in tribosystems (a system of units subject to friction), premature wear of component parts will also occur.

The difference between 5w40 motor fluid and other oils is that 40 is an average value. This product copes with the tasks set by the manufacturer, both in winter and in summer, excellently. The characteristics of semi-synthetics with index 30 are more likely to be designed for modern car brands. The difference between the above products and oils with an index of 50 and above is a wider range of applications. In the latter case, it is recommended to use the product for cars with high mileage.

In general, the differences between 5w40 and 5w30 motor fluids are not significant, however, if the engine temperature is 100-120 degrees, it is better to use 40. The viscosity will be one and a half to two times higher. For this reason, 5w40 series motor oil can be used even for internal combustion engines that have a high thermal load. Semi-synthetics are attractive because they retain their original properties at high voltages. Even at high speed shifts and high temperatures, the lubricant will create a durable film to protect spare parts.

Speaking about which oil is better to use under heavy loads on the engine, the answer is obvious - semi-synthetic with an index of 40! But when choosing between the described options for winter, you should consider 30. Perhaps it would be more rational to use this type due to the fact that it starts the power plant more efficiently when it’s cold, because it has less viscosity. At high loads, the liquid becomes too fluid.

Thus, we looked at the nuances of different oils. There is only one conclusion: you should take into account the manufacturer’s recommendations when choosing between different oils and consider the conditions under which the product will be used!

Experienced motorists are well aware that in order to select a good motor oil for a car, certain factors must be taken into account. Automakers usually recommend a certain type and even brand of lubricant, but after high mileage, many motorists switch to other oils. Especially often the choice is between two products - 5w30 or 5w40. How do they differ from each other and which liquid to choose?

Key subtleties of choice

If you don’t know which oil is thicker than 5w30 or 5w40, and which one is better for your car’s power unit, do not deviate too much from the automaker’s recommendations. There will always be recommended oils optimal choice for cars, but is there a significant difference between 5w30 and 5w40?

The main parameter of motor fluid is viscosity, that is, fluidity. According to the classification developed by the American Association of Automotive Engineers (the parameter is marked SAE on cans), each oil is assigned a double number.

The first index 5w indicates the viscosity of the oil 5w30 or 5w40 at minimum operating temperatures. The lower the ambient temperature, the thicker the oil will be and the more difficult it will be for the pump to pump it.

The second digit in this marking indicates the upper limit of the car's operating temperature. High viscosity will improve the formation of an oil film on the contacting parts of the engine. Based on their numerical values, motor oils are distinguished by their high-temperature viscosity index. Here is the real difference between 5w30 and 5w40 oil:

• in the first, the high-temperature viscosity varies from 9.3 to 12.6 mm2/s;
• the second has from 12.6 to 16.3 mm2/s.

Do not forget that the functioning of the engine as a whole depends on viscosity. If the engine of your car is designed to work with 5w30 oil, then if 5w40 is poured into it, the load on the oil pump will increase and friction will increase. In this case, oil consumption will decrease, since the higher the viscosity, the higher the hydraulic resistance will be. this will lead to oil starvation and engine wear. If you fill in 5w30 lubricant instead of the 5w40 recommended by the manufacturer, it will be too liquid for the engine. The resulting oil film will adhere worse to surfaces and increase engine wear.

Comparison of 5w30 and 5w40 oils

Let's figure out the difference between 5w30 and 5w40 oil in real operating conditions:

• At normal engine fluid temperatures reaching 120-140 degrees, the viscosity of 5w40 lubricant will be approximately 1.5 times higher.
• 5w40 is suitable for modern engines operating with increased thermal stress. This liquid retains viscosity better, therefore it retains the protective film well and prevents mechanical friction.
• The temperature range of 5w30 oil is shifted downwards, in contrast to 5w40 fluid, so the oil has a lower viscosity and makes it easier to start the engine in the cold season. At elevated temperatures, the oil becomes highly fluid, so its lubricating properties deteriorate.

What oil is best to fill in in the summer and why?

5w40 motor fluid is more viscous, so it creates a more stable and durable oil film than thinner oil. Inexperienced motorists are sure that such oil is no different during winter operation of the car, and in the summer it better protects the engine from wear, but is this true?

This statement is partly true. First of all, it matters design features engine and recommendations of the automaker. Even a slight increase in viscosity relative to normal parameters sometimes leads to deterioration in pumpability, that is, the lubricant does not penetrate the friction pairs in the required quantity.

When determining the summer viscosity parameter, you need to take into account that too thin 5w30 oil in some cases leads to fluid leaks through gaskets, seals and other seals. The oil film formed on the engine elements when pouring low-viscosity liquid may be too thin. This will increase engine wear and increase engine operating temperature.

Thus, when choosing whether 5w30 or 5w40 is better in the summer, make sure that both oils are on the list of recommended ones in the user manual. In this case, it is better to use a thicker 5w40 lubricant in summer, and a thinner 5w30 in winter.

Are the two oils compatible?

Many car owners will be interested to know not only which oil is thicker, 5w30 or 5w40, but also to find out whether they are compatible? Typically, automakers advise not to mix different motor fluids, especially those with different bases - mineral and synthetic. As for 5w40 and 5w30, they are both synthetic or semi-synthetic, so theoretically they can be combined without harm to the engine.

In this case, it is better to use oils from the same manufacturer so that there is no conflict between the additives used. By mixing oils from different manufacturers, different additives may react, causing the engine to operate incorrectly.

Properly selected motor oil will not only make your car run like a clock, but will also protect you from many unpleasant surprises on the road. The search for the ideal motor oil falls on the shoulders of the car owners themselves, who often do not delve into the essence of the motor oil labeling, do not know the difference between the 5w30 and 5w40 brands, and do not even know what their difference is. In order to make the right choice, you need to find out everything about potential “candidates”.

Is there a difference between 5w30, 5w40, 10w40, 15w40, how is it determined

Between these types of motor fluid a big difference. The symbols indicated on the engine oil label speak not only about the technical characteristics of the oil itself, but also tell the car owner which oil is right for him. The most popular oils are 5w30 and 5w40. They gained fame due to their versatility. Let's consider specifications the most popular brands of motor oil and answer the question: which is better, 5w30 or 5w40.

5w30 has a temperature range from -25ºС to +25ºС. Under such weather conditions, the oil retains all its properties, carefully protecting the engine from premature wear. 5w40, with a high content of thickening additives, has the same lower temperature limit as 5w30, but in the summer it can withstand up to +35ºС. The choice between these 5w30 oils is an eternal problem for drivers.

So which oil is better: 5w30 or 5w40? The answer is simple - the best engine oil is the one that is most suitable for the normal weather conditions of the area where your car “lives”. 10w40 suitable for areas where the thermometer does not fall below -20ºС in winter, and does not rise above 35ºС in summer. 15w40 the composition is less frost-resistant, its maximum value in the cold season is -15ºС, but in summer the oil protects the engine even at +45 degrees.

Interesting!The most heat-resistant motor oil is the oil with the “60” symbol. Above this temperature limit motor fluid not released.

Seasonality in the use of motor oil

The numbers in the name of the oil indicate the seasonal parameter of the liquid. The first number before the “W” sign is winter, the second is summer. The higher the number, the better this oil is suitable for a certain time of year, maintaining its thickness and the necessary consistency for driving the mechanism. Brands 5w30, 5w40, 10w40 and automobile oil 15w40 are all-season, which means they can be used both in summer and in winter time. If the oil marking has only one number, then such motor fluid is intended only for one season (with the letter “W” - winter; only the number - summer).

Important! Seasonal types of oils must be used according to the instructions. After all, with summer oil at temperatures below zero, the engine will not start, and winter oil is powerless at high temperatures.

At very low temperatures, paraffins are formed in the oil, which affect its “fluidity.” Solidified oil not only cannot lubricate the engine, but can also damage it. This once again shows how important it is to know the technical characteristics of 5w30 and 5w40 oils and understand their differences. Using oil even with a deviation of a couple of degrees from the specified norm can render the engine unusable.

Ignoring the rules for using oil in the summer also has serious consequences. At high temperatures, the lubricant thins out, and the oil film that protects spare parts from friction becomes thinner. Oils with insufficient viscosity will not pass this strength test.

Remember! The SAE symbol on the can indicates that the motor oil meets viscosity standards, and does not indicate its “seasonality.”

Oils 5w30, 5w40, 10w40, 15w40 - which oil is better for a “worn out” engine

We have already found out how 5w40 oil differs from 5w30 and what are the features of oils (according to SAE classification) 10w40 and 15w40. But how important is this difference for a “worn out” engine and does such an engine require special care?

As the part is used, all motors gradually wear out and their operation becomes less smooth. This is a normal phenomenon for any mechanism, so every driver should be a little more attentive to his car and, at the first “symptoms of old age,” slightly change his usual care strategy.

Signs of engine wear:

high engine oil consumption;

Exhaust with smoke;

Black carbon deposits on spark plugs;

Engine malfunctions at idle speed;

High fuel consumption;

Frequent engine overheating.

These symptoms should make you think about preventative measures for the operation of the engine and its parts, and about changing the brand of oil. If previously you were choosing between 5w30 or 5w40 oil, the interpretation of which differs only in the level of viscosity, now this dilemma will be solved for you once and for all. From now on, your choice will fall only on brands of oils with a high content of thickening additives, that is, more viscous.

The main rule for operating a worn engine is to increase the viscosity of the oil. If earlier you preferred brands of oils with the “30” mark, now you need to buy forty, and if you took “40”, then it’s time to switch to fifty. For example, 15w40 engine oil can be replaced with 20w40, the viscosity of which is much higher.

By increasing viscosity, you reduce the friction force of mechanism parts and increase their resistance. The main thing to remember is that each brand of oil has its own temperature range. And if the oil you have chosen suits you in terms of viscosity, but is not suitable for winter use, then it is worth purchasing a separate winter brand.

Interesting fact! « Synthetic oils and worn-out engines are incompatible” - this is one of the most common myths. But why do many manufacturers recommend 10w40 oil, the interpretation of which indicates a high synthetic content in its composition? Because they know better which oil is suitable for the old engine.

The modern market for automotive lubricants offers a large selection of oils, and this is a huge plus, because with such an assortment it is much easier to find the ideal option.

Many people are familiar with this picture: a frosty morning and two car enthusiasts making their four-wheeled “friends.” One, the owner of a well-deserved “pensioner,” started it, as they say, “with half a kick,” and his neighbor in a brand new car scares those around him with the ineffective howling of the starter until the battery is completely discharged.

How so? The car is new, the manufacturer guaranteed reliable starting even at lower temperatures! And the problem, in most cases, is the engine oil filled in for the winter. And not in the vehicle itself.

The main parameters that you should pay attention to when choosing engine oil for winter

When operating the vehicle in winter period When choosing a motor oil, a car enthusiast should pay special attention to three of them, which are directly responsible for starting and trouble-free operation of the engine in Russian winter conditions.

Viscosity

The main parameter is viscosity. Everyone without exception has heard about him. But hearing this is one thing, but understanding what it is is completely different. In a nutshell, viscosity is the ability of an oil to maintain its properties within a certain temperature range. Simply put, lubricating and reducing the friction between parts is equally good both at minus twenty and at positive temperatures. And if it’s quite simple - do not freeze and do not boil.

Video - which engine oil is the best:

It is the viscosity indicator that the manufacturer indicates when labeling its products, in SAE system. For example, let's take one of the most common all-season oils SAE 5W40, where the number five is responsible for the viscosity at negative values, and 40 - for positive ones.

It should be remembered that this is just a “number”, not an indicator of temperature conditions!

Turnability and pumpability

But there are two more parameters that directly depend on viscosity, but are no less important when choosing engine oil for winter. Namely: crankability and pumpability. But the manufacturer no longer directly talks about this. We'll talk about them in more detail a little later.

Table of oils for cars by temperature

For now, let's see which SAE markings correspond to different temperature conditions.

Remember we asked you not to confuse the marking number with the ambient temperature at which the oil can be used? The table below clearly shows which value corresponds to a certain threshold.

How less value the first number of markings, the higher the possibility of using the car in winter.

The first four oils are purely winter oils; use in summer is prohibited. Next are four of their comrades, but in the neighboring summer “workshop”. Both the first and second groups are used nowadays only by very meticulous car enthusiasts.

Most people prefer the so-called all-season motor oil. And as we see, some of them are capable of seriously competing with their “pure” counterparts. And no matter what you say, it’s convenient. Therefore, in the future we will talk specifically about all-season oils.

Video - what kind of engine oil to pour into the engine:

So which engine oil is best to use in winter? The answer to this question is very easy to find in the owner's manual for the car. There the manufacturer answers it quite categorically. But there are two problems here. The first is mentality. Almost any resident of our country will look at the instructions only when they break something. Secondly, there is simply no such book at hand.

Therefore, we will figure it out ourselves and it’s time to remember the parameters mentioned above: crankability and pumpability. The essence is clear from the names themselves. Pumpability is the ability of oil to pass through the engine system under the influence of the oil pump, and crankability, accordingly, is responsible for cold starts at low temperatures environment.

But how do they relate to viscosity? The table will help us.

And what can be seen from it? The mentioned parameters, superimposed on the temperature scale, differ significantly from viscosity indicators.

Consider an oil labeled 5W40. The minimum pumpability is minus thirty-five degrees, the maximum is plus forty. Turnability - minus twenty-seven. What do we have in the viscosity table? Operation at minus thirty is allowed. Here is the first underwater pebble. Look, only oil with the number zero has the best performance in these indicators.

Therefore, we can draw a preliminary conclusion.

Which oil is better in winter: 5W30 or 5W40?

For most regions Russian Federation There is absolutely no point in purchasing oils with a lower viscosity threshold of less than 5. The ideal option is a pair of 5W30 and 5W40.

Well, you say, they sang “war songs” here, and now we have to choose one of two? Absolutely true, but we propose to do this together by simple comparison discussed parameters.

According to the parameters declared by the manufacturer for the winter period of operation, 5W30 oil is superior to its “fortieth” competitor 5W40!

But we remember that both of these products are like twins in terms of pumpability and cranking parameters. And which one to choose?

It sounds a little paradoxical, but this happens quite often in life. When choosing a motor oil for the winter, you should pay attention to the summer characteristics. Our winter is long, but not endless, and if you do not plan to change your oil in the spring, you should think about the upcoming warm days. Agree, it’s autumn, winter, but I remember the sun, the sea, relaxation...

And here we see that SAE 5W40 is a confident leader both in viscosity (operation at +30) and maximum pumpability (the indicator reaches +40). The winner is determined: of this pair of oils (5w30 or 5w40), it is better to use 5W40 if you do not change the oil in the summer.

Diesel and gasoline power unit

“How, how can it be,” the skeptic will say, “I have diesel car, everything is different for me.” And no one will argue with him. Oil for diesel and gasoline engines is indeed qualitatively different. This is due to different operating principles of power units and fuel types.

Diesel fuel, even if it is of high quality, due to its chemical composition produces more soot and soot, which, in addition to its main functions, is what engine oil combats. Therefore, diesel oils contain large quantity detergent additives. In addition, diesel oils have a higher alkalinity number, which reduces the harmful effects of the acidic environment inherent in diesel combustion processes.

American and European automakers have developed two additional standards dividing oils into gasoline and diesel: API and ACEA respectively.

In the first case, the letter S indicates oil for a gasoline engine, C indicates a diesel engine. In the second: A – gasoline, B – diesel.

Also, these standards divide oils by engine type depending on the timing of production and purpose (two-stroke, four-stroke, passenger cars, trucks, and so on). This classification is indicated by the second letter of the marking.

For clarity, the tables are given below:

for gasoline engines

for diesel engines

Undoubtedly, these indicators should be taken into account, but they in no way cancel the SAE standard. The degree of viscosity and other related parameters are the same for both diesel and gasoline oils.

In any case, the label of each oil will definitely have an SAE indicator, but API or ACEA comes with additional markings, and even then not always.

And if we talk about the type of oil for diesel operation in winter, experts advise using oil intended for diesel engines. The fact is that currently manufacturers have released onto the market many universal oils suitable for both types of power plants, combining almost incompatible things.

The main thing here is to be careful. If the canister bears the API designation with the first letter S (SJ/CF) - this product is a priority for gasoline engines, the letter C (CF/SJ) is a priority for diesel engines.

But versatility is not always good or convenient. According to the results of studies, such oils very much depend on the quality of the fuel used: the lower it is, the shorter the service life of the oil and, accordingly, its useful properties. We won’t talk about the quality of fuel in our country, this is superfluous.

Climatic conditions in different regions

An equally important factor when choosing motor oil is the region of residence, its climatic conditions. All of the above comes to moderate climatic zone countries: it’s hot in summer, in winter it’s hard to get a tooth on your teeth.

But if you live in the south, where there is not always snow in the winter, it is worth considering oils that are more oriented towards warm and hot weather.

What about those places where there are polar bears? From surveys conducted by both motorists and professionals operating vehicles in the Far North, we came to the conclusion that the vast majority use SAE 5W40.

The lower operating threshold is somewhat arbitrary, and you won’t be able to start the engine at minus forty without installing heating systems with absolutely any oil, so why “fence the garden”?

Particularly attentive and picky readers may notice why they made a reservation at the very beginning: “so-called all-season oils.” But we didn’t make a reservation. To make it clear what exactly we had in mind, here is a conversation between two car enthusiasts starting their cars in the morning.

One is already purring and warming up, the second is not at all. The upset owner asks the “lucky” one: “What kind of oil are you using?” The answer is fresh. It’s a joke, of course, but as you know, every joke contains only a fraction of a joke.

The word all-season has already played a cruel joke on many car enthusiasts. The fact is that if the oil is changed in the spring, by winter the engine crankcase will not contain the same product that you took off the shelf in the store.

It is difficult to say in what percentage these same properties are reduced per thousand, but if this were not so, there would be no need to change it. Right?

Currently, the automobile fleet of the Russian Federation mainly consists of cars whose engines and operating conditions require oils of the 5W30 or 5W40 category. Below we will briefly look at 5W30 and 5W40 oils, what is the difference between them, whether they can be mixed, and which SAE class lubricant is best suited for winter.

Interpretation of oil 5W30 and 5W40

Similarly, two numbers separated by the Latin letter “W” designate all-season oils according to the SAE J300 classifier. In fact, the difference between the lubricants under consideration is small.

Oils 5W30 and 5W40 have the same winter viscosity: 5W. This means that the oil has the following qualities during winter use:

• viscosity when pumping lubricant through the system is guaranteed at ambient temperatures down to –35° C;
• viscosity when cranking the crankshaft will ensure that the engine starts with a starter and at the same time protect the crankshaft bearings and journals, as well as the camshaft covers and beds from scuffing at ambient temperatures down to –30° C.

And for the two oils under consideration this figure is the same. That is, there is no difference regarding winter operation.

The so-called summer part of the index according to SAE speaks of the kinematic and dynamic viscosity at the operating temperature of the oil. There are already quite significant differences here. For 5W30 oil, the kinematic viscosity at 100° C ranges from 9.3 to 12.5 cSt, and the dynamic viscosity at 150° C is 2.9 cSt. For 5W40 oil, respectively, from 12.5 to 16.3 cSt and 3.5 cSp.

Is it possible to mix 5w30 and 5w40?

This question is not entirely correct, since other factors affect the miscibility of oils. But this question is still often asked by motorists. Therefore, we will give an explanation.

You can mix oils with the same bases and similar additive packages without restrictions. For example, if you fill in hydrocracked synthetics (or semi-synthetics, if we take into account the Western classification) with an additive package from Lubrizol, you can safely add oil with the same base and additives from Lubrizol. The difference will be only in the concentration of thickening components and insignificant differences in other active substances. Oils will not conflict with each other. Moreover, this statement is true regardless of the oil manufacturer.

You cannot mix 5W30 and 5W40 oils, which have different origins. For example, pouring 5W30 mineral water into high-quality 5W40 PAO synthetic is undesirable. The differences between these lubricants at the molecular level are significant. Such mixing can lead to increased foaming, decomposition of some additive components, formation of ballast chemical compounds and their precipitation, as well as some other unpleasant side effects.

What is thicker: 5w30 or 5w40?

Based on the first point, the answer to this question is: thicker oil with a viscosity of 5W40. Both in terms of dynamic viscosity (at high-speed shear) and in terms of kinematic viscosity. However, it is impossible to say unequivocally that one of the oils is better or worse just because it is thicker.

The viscosity parameter is not assessed only in the better/worse plane. In addition to the viscosity itself, which is definitely higher for 5W40 oil, an important indicator is the viscosity coefficient. This indicator characterizes the ability of the oil to maintain its viscosity characteristics over a wide temperature range. And the higher this indicator, the less the oil characteristics depend on temperature.

For example, with a viscosity index of 140 units, the oil will significantly change its fluidity with temperature changes. At negative temperatures it will noticeably thicken, and at positive temperatures it will become more fluid. At the same time, a viscosity coefficient of 180 units indicates a lesser dependence of viscosity on temperature changes. That is, the oil is more stable in terms of viscosity over a wide temperature range.

Oil for winter: 5W30 or 5W40?

In terms of cold start safety, both oils under consideration will work equally well in the engine in winter. Guaranteed engine protection is provided at temperatures down to –30° C. There is no or insignificant difference for winter operation.

We discussed above how the “summer” part of the viscosity index differs. And how this will affect winter operation depends only on the engine itself. If it is designed to work with oil whose high-temperature viscosity should be 30 units according to SAE, 5W30 oil will be better for winter. If the engine requires 5W40 lubricant, it is better not to experiment and pour it with it.

Which oil is better: 5W30 or 5W40?

Initially, the automaker includes certain parameters in the engine design: gaps between contacting parts, maximum loads in friction pairs, roughness of mating surfaces, etc. And the oil is selected in such a way that it easily penetrates the contact spots, forms a reliable protective film and minimizes metal contact on metal.

Therefore, the conclusion here is simple: better is the oil that is initially more technologically advanced and of higher quality and is recommended by the automaker. There is a small caveat here that not all motorists are aware of. For some car models, the automaker may recommend different oils for different conditions operation or mileage. Therefore, it will not be superfluous to once again leaf through the instruction manual and look at the section with recommended oils.