A large number of products and variety on the fuel and lubricants market have recently been the main reason that the selection of engine oil involves certain difficulties. Motorists constantly focus not only on quality, but also on issues of seasonality, mixing, compatibility and interchangeability of oils of various brands.
It is also well known that the viscosity index of a lubricant is one of the key parameters along with the base base used in the manufacture of a lubricant (). In other words, the quality and price of the product will depend on the base and additive package.
With regard to viscosity, this parameter determines both the general possibility of using a lubricant in a particular engine, taking into account the recommendations of the power unit manufacturer itself, and the expediency of operating an internal combustion engine on a product with a particular viscosity.
In this article, we intend to talk about popular oils 5w30 and 5w40, what is the difference between these products, what are the characteristics of 5w30 and 5w40 oils, is it possible to fill in 5w40 oil instead of 5w30, and which oil is better, 5w30 or 5w40 in winter and summer.
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Engine oil viscosity and seasonality
Let's start with what many drivers have heard and some have come across a situation when the engine cannot be started in winter due to the fact that the lubricant thickens heavily in the crankcase. This means that with a charged and fully functional starter, it is still not possible to crank the crankshaft at the required frequency, which is necessary for starting.
It turns out that in this case the material has too high a viscosity and is not suitable for use in winter conditions. In other words, the so-called seasonality of fuel and lubricants for the engine was not taken into account. This is not surprising, since today there is no clear division into summer and winter products.
The entire modern classification of oils boils down to the fact that the driver can choose a product from the catalogs of multigrade engine oil. These lubricants have different viscosities, tolerances, base bases and additive packages. Moreover, in recent years, the use that can be equally poured into both gasoline and diesel engines has been increasingly practiced.
So, back to the conventional classification by season:
- Without going into details, the so-called summer grease has a high viscosity index (index), which allows the material to work normally in the engine when the outside temperature does not drop below zero. At the same time, a more viscous product forms a "thick" protective film on the parts, reliably protecting the surfaces from wear.
- Winter lubricant has a low viscosity, such a lubricant allows you to start the engine in severe frosts without much difficulty. However, a more "liquid", low-viscosity substance, after warming up the internal combustion engine, forms a thin protective film, inferior in the quality of engine protection to summer counterparts.
- Multigrade engine oil, unlike winter and summer oil, does not imply seasonal replacement, that is, it does not need to be changed seasonally and can be operated all year round. Taking into account that almost all modern products are all-season, such products represent the optimal balance, combining the necessary properties for summer and are modernly suitable for winter use.
In order to separate lubricants, taking into account the dependence of the viscosity index on temperature, there is a special classification according to SAE (a specification that was developed by the Society of Automobile Engineers). The SAE classifier determines that summer products are rated between 20 and 60. Winter lubricants are rated from 0W or 5W to 25W.
The combination of these two indicators is separately indicated on multigrade oil and is well known to motorists (for example, oil 0W20, 5W30, 10W40, etc.). Now let's figure out what the viscosity of the popular 5w30 and 5w40 oil is, as well as what exactly the decoding of 5w30 and 5w40 oils will mean. We add that the topic of choosing a 5w30 or 5w40 oil for assumes the same answers to the questions posed in this article.
What is the difference between 5w30 engine oil and 5w40
In order to accurately determine the viscosity of an all-season grease in winter and summer, it is necessary to look at the numbers before and after the letter W in the designation. The specified letter is an abbreviation for Winter (English winter). For example, 5W30 indicates that 5W indicates the SAE viscosity at low temperatures.
The number 30 is the SAE temperature rating for product performance at high temperatures. Both the ease of starting, the fluidity and pumpability of cold grease in winter, and the stability of the protective film on the surface of loaded parts at maximum temperatures will depend on these two specifications.
If you ask the question, what is the difference between 5w40 oil and 5w30, then it should be noted that these oils have identical indicators that characterize suitability for winter operation. The 5W classification clearly indicates that such an oil provides a confident start of the internal combustion engine down to -30 degrees of frost.
Now let's take a look at the SAE high temperature viscosity, that is, the difference between 5w30 and 5w40. General comparative analysis of the data indicates that the kinematic viscosity of 5W30 when heated to 100 degrees Celsius is from 9.3 to 12.5 mm2 / sec. At the same time, 5W40 under similar conditions has a viscosity index from 12.5 to 16.3 mm2 / sec.
This comparison also shows that the minimum HTHS viscosity in the case of 5W30 is at around 2.9. At the same time, for 5W40 this value is also 2.9, while the parameter can reach 3.7, which is noticeably higher.
The above data allows you to determine which oil is thinner, 5w30 or 5w40. In simple words, under high heating conditions, 5W40 differs markedly from its counterpart 5W30 in terms of high-temperature viscosity. Otherwise, the answer to the frequent question of which oil is thicker, 5W40 or 5W30, will be exactly the first option, that is, 5w40.
Which oil is better: 5w30 or 5w40 in summer
Considering that 5W40 oil is more viscous, it creates a strong and stable oil film on the surface of parts in comparison with the competitor. As it might seem at first glance, such a product is no different during winter operation and protects the engine better in summer.
Note that this statement is only partially true. First of all, you need to take into account the design features of a particular internal combustion engine, as well as individual recommendations of the motor manufacturers. The fact is that even a slight increase in the viscosity of the oil in some units can lead to the fact that pumpability becomes worse, that is, the lubricant will not flow to the friction pairs in the proper amount.
Also, when choosing a summer viscosity index, it should be borne in mind that too "liquid" lubricant (for example, 5w30) can lead to leakage of lubricant through oil seals, gaskets and other seals. When low-viscosity oils are used, the oil film on the parts can turn out to be thin, as a result of which the wear of the assemblies increases significantly, the temperature of the internal combustion engine rises.
In other words, before opting for 5W40 or 5W30, you must:
- Separately, make sure that both types of oil are on the manufacturer's recommended list for a particular motor.
- Also, it will not be superfluous to take into account the peculiarities of engine operation.
For example, a viscosity index of 30 means that the declared characteristic of the engine oil will be maintained at operating temperatures only up to 150 degrees.
If the car is located in a region where the outside air temperature rises significantly in summer, while the driver constantly "turns" the engine to high revs, practices an aggressive driving style and heavily loads the power unit, then the oil temperature will be as high as possible. In this case, it is worth thinking about increasing the "summer" viscosity index.
Compatibility of oils 5w30 and 5w40
Quite often, especially in the event of an emergency, it becomes necessary to add oil to the engine. In such a situation, the lubricant of the very manufacturer whose product was initially poured into the power unit is far from always at hand.
The same is true for the viscosity index. For this reason, it is important to know if 5w30 and 5w40 oils can be mixed. At the very beginning, we note that it is often not particularly recommended to mix mineral oils with products in which the base is completely synthetic. In other words, mineral water cannot be mixed with synthetics. It is also not recommended to mix semisynthetics with synthetics, etc.
As for 5W30 and 5W40, it is theoretically possible to mix these oils with minimal risks if both products are from the same manufacturer. In an emergency, it is allowed to mix oils from different manufacturers, but only taking into account that they have the same base base.
This means that mineral oil is mixed only with mineral oil, semi-synthetics with a similar product, etc. At the same time, it still does not work to give an unambiguous answer to the question of whether it is possible to add 5w40 to 5w30 oil. The fact is that for each type of oil, manufacturers use special additive packages that can react after mixing.
In any case, even if there are no obvious consequences after topping up, it is still an emergency measure. After repairing the breakdown, immediately drain such a mixed grease from the engine,. Also, in some cases, it may be needed additionally.
Let's summarize
In view of the above, it becomes clear that the viscosity of the oil and the stability of this characteristic at different temperatures determines the main characteristics of the lubricant, as well as the price of the product.
The best choice can be considered an oil in which the viscosity indicators are within the tolerances of the ICE manufacturer. In parallel, you should pay attention to the base base, since a more expensive semi-synthetic oil, for example 5W40, will be better in terms of service life and quality compared to the same, but mineral 5W40.
For owners of old cars, the choice of oil must be approached with special responsibility. On the one hand, there is an intensive development of technologies in the field of production of fuels and lubricants. This means that the information on lubricants in the operating instructions may be outdated.
Moreover, if you have to select the lubricant yourself, you need to take into account a number of features that we talked about above. To put it simply, not always expensive low-viscosity synthetics will mean that the old engine on such modern high-tech oil is reliably protected in summer and winter.
Finally, we add that when choosing an oil, you need to adhere to a certain middle, and also take into account the individual characteristics of the operation of the internal combustion engine. This means that the lubricant should not strongly liquefy and lose its properties, taking into account the maximum possible heating, and also remain fluid with the onset of cold weather.
Read also
Features of the selection of engine oil for winter. What kind of oil among the all-season ones is considered winter according to the marking, what should be taken into account when choosing.
Viscosity is the most important property of an oil. Its change depending on temperature determines the limits of the temperature range of the oil application. At low temperatures, the oil should not have a high viscosity in order to ensure a cold start of the engine (cranking with a starter) and pumping through the lubrication system. At high temperatures, the oil should not have a very low viscosity in order to maintain the required pressure in the system and reliably create a lubricating film between the rubbing parts.
According to the viscosity and its change depending on the temperature, the oils are divided into:
Winter - due to their low viscosity, they provide a cold start at low temperatures, but do not provide reliable engine lubrication at high temperatures;
Summer - do not provide cold start at ambient temperatures below 0 ° C, but due to high viscosity they reliably lubricate the engine at high temperatures;
All-season - at low temperatures they have the viscosity of winter oils, and at high temperatures - summer oils. All-season oils displace summer and winter oils for two reasons: there is no need to replace them when changing the season and they are more efficient as energy saving.
In addition to viscosity, the performance characteristics of the oil are determined by anti-wear detergent, antioxidant and anti-corrosion properties.
Viscosity characteristics are thus the first and most important elements in the classification of engine oils. Any additives, including modifiers, increase its price, so it is always necessary to choose the right ratio of oil properties and operating conditions.
The basis for the selection of a specific brand is the requirements of the manufacturer of your car for the oils and fluids used, given in the operating instructions. Usually, in addition to the formal requirements (specifications) for the products used, there are also specific oil brands or references to lubricant manufacturers as an example. If the car is already far from new and the information given in the operating instructions is not enough (or they are simply outdated), then you must independently choose the brand of oil for the engine or transmission.
What is "SAE"?
SAE specification (SAE - Society of Automobile Engineers)- Society of Automotive Engineers) is an international standard governing the viscosity of oils.
THIS IS NOT A BRAND OF OIL MANUFACTURER IN NO EVENT !!!
It must be remembered that the SAE specification does not speak about the quality characteristics of oils, or their use for specific car brands and types of engines.
Read the SAE specification for engine oils:
Kinematic viscosity... It characterizes the belonging of seasonal oils to one or another viscosity class. Determined at 100 ° C and low shear rates (from 20 to 100 s-1).
Starting properties... They characterize resistance when starting a cold engine and the ability to achieve starting speed. Determined at negative temperatures from -10 to -35 ° C, depending on the viscosity class and high, about 105 s-1, shear rates. In other words, under conditions typical for operation in crankshaft bearings during a cold start.
Pumpability... It characterizes the rate of oil flow to friction pairs during cold start and the likelihood of engine failure due to rotation of the liners during cold start. Determined at negative, from -15 to -40 ° C, temperatures depending on the viscosity class and low, about 10 s-1, shear rates. Thus, when evaluating this characteristic, the conditions for the flow of oil in the sump to the oil receiver and in the oil receiver of the pump are realized when starting a cold engine.
Viscosity at high temperature... Reflects the effective, real viscosity of the oil during summer operation of modern highly loaded engines. It characterizes the antiwear properties of oils, friction losses and the impact on engine efficiency. Determined at 150 ° C and high, of the order of 106 s-1, shear rates. This simulates the loading conditions of the crankshaft bearings when operating with high loads and temperatures.
As you can see, the SAE specification is the characteristics of oils in terms of viscosity grades. Today it contains 6 winter grades and 5 summer grades of oils. In the designation of winter classes there is the letter "W" from the word "Winter", which means "Winter". The higher the viscosity of the oil according to this specification, the higher the number included in the class designation.
Winter viscosity grades include: SAE 0W, 5W, 10W, 15W, 20W, 25W;
Summer viscosity grades include: SAE 20, 30, 40, 50, 60.
For example, let's take a look at what, for example, the designation SAE 10W-40 for engine oils says. The designation of the viscosity grade "10W" gives us information about the winter use of this oil. In other words, the correct choice of this parameter will depend on how easy, and most importantly, without negative consequences, you can start the engine in the cold.
The viscosity grade "40" in our example is the so-called "summer" grade and indicates how much the oil is able to maintain performance in high-temperature zones of the engine.
The presence in the designation of two classes at once (as in our example - SAE 10W-40) indicates the all-season nature of this oil.
How to choose an SAE viscosity grade?
When choosing an engine oil viscosity grade, follow the instructions of your vehicle manufacturer. If it is absent or does not contain such recommendations (for example, if the car is far from new and the recommendations in the instructions are either already outdated or simply absent), you should remember that:
a) When choosing the so-called "winter" viscosity grade, you must be guided by the values of the average winter temperatures in the region where your car is operated.
Following these recommendations, you and your car will be insured against problems with starting in winter and against negative consequences for the engine (such as increased wear and "seizure" during and immediately after starting, when the engine is operating in oil "starvation" mode), which usually occur when using oils of the wrong viscosity class. It must be remembered that every time the engine is started (not necessarily in severe frost, but even at positive temperatures), it takes some time for the oil pump to pump oil through the lubrication system and it goes to all rubbing parts. At this time, the engine will operate in the so-called oil "starvation" mode, which we have already mentioned above. It is clear that friction and wear increase sharply in this case. Thus, the more the oil is able to maintain fluidity at low temperatures, the faster it will be pumped through the lubrication system and provide engine protection. The best in this respect are motor oils of the "0W" class.
c) With regard to the choice of the so-called "summer" class, it should be noted that most European car manufacturers recommend the use of oils of class "40" according to SAE. This is due to the high thermal stress of modern internal combustion engines and the presence of high temperatures, specific pressures and shear rates in various zones of the engine (piston rings, camshaft, crankshaft bearings, etc.). Under these harsh conditions, the oil must maintain a viscosity sufficient to form an oil film and cool the friction pairs. This task becomes especially relevant to prevent increased wear, scuffing and "jamming" in the heat or during a long stay in a "traffic jam" (in the absence of blowing and cooling the engine by flows of oncoming air and, as a result, overheating of the oil in the engine crankcase), and also in case of engine overheating due to possible malfunctions in the cooling system.
For multigrade oils with the properties of both winter and summer grades of oil, the SAE specification provides for a double designation, for example, 10W-40, where winter viscosity-temperature properties are reflected on the left side of the designation, and summer - on the right.
Viscosity-temperature properties are one of the most important characteristics of engine oil. These properties determine the ambient temperature range in which this oil provides engine start without preheating, unhindered oil pumping through the lubrication system, reliable lubrication and cooling of engine parts at the highest permissible loads and ambient temperatures. Even in moderate climatic conditions, the range of oil temperature change from cold start in winter to maximum warming up in the crankshaft bearings or in the piston ring zone is up to 180-190 ° C. The viscosity of mineral oils in the temperature range from -30 to +150 ° C changes thousands of times. Summer oils with sufficient viscosity at high temperatures allow the engine to start at an ambient temperature of about 0 ° C. Winter oils that provide a cold start at low temperatures have insufficient viscosity at high temperatures. Thus, seasonal oils, regardless of their operating time (vehicle mileage), must be changed twice a year. This complicates and increases the cost of engine operation. The problem was solved by creating multigrade oils thickened with polymer additives (polymethacrylates, copolymers of olefins, polyisobutylenes, hydrogenated copolymers of styrene with dienes, etc.).
The viscosity-temperature properties of thickened oils are such that at negative temperatures they are similar to winter ones, and at high temperatures - to summer ones (Fig. 2.3).
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Rice. 2.3. Viscosity-temperature characteristics on the example of summer (7 - SAE 40), winter (2 - SAE 10W) and
multigrade (3 - SAE 10W-40) oils:
4 - maximum viscosity at cold start;
5 - minimum required high-temperature viscosity
Viscous additives relatively little increase the viscosity of the base oil at low temperatures, but significantly increase it at high temperatures, which is due to the increase in the volume of macropolymer molecules with increasing temperature and a number of other effects.
Unlike seasonal oils, thickened multigrade oils change viscosity under the influence of not only temperature, but also shear rate, and this change is temporary. With a decrease in the speed of relative movement of the lubricated parts, the viscosity will increase, and with an increase, it decreases. This effect is more pronounced at low temperatures, but persists even at high temperatures, which has two positive consequences: a decrease in viscosity at the beginning of cranking a cold engine with a starter facilitates starting, and a slight decrease in oil viscosity in the gaps between the friction surfaces of parts of a heated engine reduces frictional energy losses and gives fuel economy.
The characteristics of the viscosity-temperature properties are the kinematic viscosity, determined in capillary viscometers, and the dynamic viscosity, measured at different shear rate gradients in rotary viscometers, as well as the viscosity index - a dimensionless flatness indicator of the viscosity-temperature dependence (see Fig. 2.3), calculated from
the values of the kinematic viscosity of the oil, measured at 40 and 100 "C (GOST 25371-82). In the normative documentation for winter oils, the kinematic viscosity at low temperatures is sometimes normalized. The viscosity index of mineral oils without viscous additives is 85-100. It depends on the hydrocarbon composition and the depth of refining of oil fractions Deepening of refining increased the viscosity index, but reduced the refined yield.
Synthetic base components have a viscosity index of 120-150, which makes it possible to obtain on their basis multigrade oils with a very wide temperature range of performance.
The low-temperature characteristics of oils include the pour point, at which the oil does not flow under the influence of gravity, i.e. loses fluidity. It should be 5-7 ° C lower than the temperature at which the oil should provide pumpability. In most cases, the solidification of engine oils is due to the formation of paraffin crystals in the volume of the cooled oil. The pour point required by regulatory documents is achieved by dewaxing the base components and / or by introducing depressants (polymethacrylates, alkylnaphthalenes, etc.) into the engine oil.
The main purpose of motor lubricants is to protect engine elements from dry friction and to ensure normal operation of the power unit while maintaining the tightness of the cylinders. With the correct selection of oil, the engine will function properly for a long time. 5W30 oil is the most popular among famous brands of synthetic lubricants.
Description of domestic lubricant products
The largest domestic producers of lubricating fluids, Rosneft and Lukoil, guarantee the high quality of their oil products. Synthetic engine oil5 W 30, produced here, is included in an acceptable price category, this grease is perfectly adapted for the operation of many types of power units in domestic climatic conditions.
Motor oils 5W30, manufactured in Russia, are also successfully used at high ambient temperatures, which is acceptable for use in warm latitudes.
What does the symbolism on the engine oil label mean?
When purchasing lubricating fluids, buyers ask themselves what is the decoding of 5W30, what kind of information is contained in the inscription, what type of product to give preference to. Decoding engine oil is necessary to make the right choice of lubricant products.
SAE 5W30 stands for:
- Subtract 30 from the number 5, resulting in minus 25. A temperature of –25˚C is acceptable for starting a cold engine.
- The letter W corresponds to the first letter of the word Winter and means the possibility of using this brand in northern latitudes.
- The number in front of W is used to determine the speed of oil movement at high temperatures in a running engine.
- The value of the number located after W characterizes the viscosity of the oil when the engine is warm.
Due to the fact that the domestic climatic conditions of car operation differ sharply, it is necessary to select lubricants after a careful study of the inscriptions on the product. The marking on the label corresponds to the special SAE viscosity classification of oils.
This classification helps you choose the right brand of grease for your vehicle according to its technical characteristics, depending on the temperature regime in which the 5W30 motor oil will be used.
Benefits of using SAE 5W 30 grease
5W30 synthetic oil has undeniable advantages. The excellent characteristics of this material contribute to the stable operation of engines when operating in adverse urban conditions, which have a negative effect on the elements of the motors:
- long idle operation;
- finding a car in traffic congestion (traffic jams);
- operation of the machine over short distances;
- increased dust content in the atmosphere.
The correct selection of the oil product contributes to an increase in the duration of the operation of the motors. Due to the unique formula and the presence of special additives that motor oil 5W30 has, these lubricants have properties that provide the following functions:
- protection of the elements of the power unit from premature destruction;
- reduction of the harmful effects of corrosion;
- removal of carbon layers from working surfaces;
- cooling of parts and assemblies of a working engine.
Engine oil 5W30 can withstand temperatures inside a working power unit equal to 150 ˚C, without changing its valuable qualities. Choosing oil for the engine of a particular car, you need to be based on the recommendations that are contained in the technical specifications compiled by the automakers.
Tolerances for the brand of car oil are not established for this model of the machine, but for the direct engine. Despite the brand's popularity, it is necessary to choose a lubricant that has parameters that meet the requirements set forth by the manufacturer of this car.
Features of the chemical composition of oil products
The additives in SAE 30 motor oils are designed to perform very specific functions. Thanks to a balanced set of additives, oil fluids become suitable for use in specific engines. Each type of grease has additives in accordance with standard engine oil regulations.
Which car oils to use depends on the choice of the car owner. Based on the age of the car, engine characteristics, speed modes, the owner prefers a certain type of oil:
- Mineral oil.
- Synthetics or semi-synthetics.
It is believed that the use of mineral lubricants in machines manufactured more than five years ago leads to a reduction in oil consumption and increases the life of the engine.
If an imported modern power unit is installed under the hood of the car, it is recommended to use synthetic lubricants. In this series is a synthetic motor oil SAE 5W30, belonging to renowned global brands, capable of withstanding climatic changes and the intensity of traffic in the city.
Oil liquid test
Before obtaining a certificate of quality, oils are tested and a chemical analysis is performed. The canister labels contain information on the conformity of the characteristics of the lubricant with the requirements of the standards. Test data is provided for consumer information.
Testing of oils takes place in laboratory conditions on special stands. A test is carried out to check the viscosity of the lubricant depending on the temperature inside the running motor.
This type of diagnostics allows you to determine the possibility of starting a cold engine in frost and the degree of protection of the motor from overheating in hot weather. The test carried out shows the thickness of the protective film formed on the rubbing surfaces of working parts and its change as a result of an increase in the internal temperature of the engine.
The test allows consumers to familiarize themselves with the features of lubricants produced by various manufacturers.
Types of lubricants depending on the type of engine
There are three categories of motor oils on the market:
- grease for gasoline power units;
- diesel oil;
- universal lubricant.
The main property of any type of lubricant is viscosity, which characterizes the ability to maintain fluidity and remain on rubbing surfaces when the temperature of parts and assemblies of a running engine rises.
In the manufacture of 5W 30 diesel lubricants, additives are added using the latest nanotechnology. Their use improves protective functions and reduces the amount of harmful exhaust gases. These synthetic additives contain minimal amounts of sulfur, chlorine and phosphorus inclusions.
Diesel oils have the characteristics recommended for use in diesel power units:
- High speed of reaching and covering parts due to the optimum flow of the lubricant.
- Maintaining normal working pressure in the engine under any load.
- The presence of a guaranteed protective film on parts at high and low temperatures.
- Reduced diesel consumption.
- Reducing the amount of carbon dioxide in the exhaust.
It is not recommended to pour 5W 30 synthetics into a turbocharged engine; semi-synthetic oil with a low viscosity is more suitable for this type of engine. Semi-synthetics help to improve the environmental parameters of power units.
Low-viscosity energy-saving lubricants are recommended for use in the engines of cars operated in the European Union and Japan, where the environmental situation is subject to increased control.
To avoid purchasing a counterfeit lubricant, you only need to visit 30 specialized outlets. When buying a lubricant of a well-known world brand, you need to carefully examine the quality of the product packaging, lids and labels.
The canister must be free of scratches and abrasions. The protective ring under the cover must be free of movement and damage. The label must be decorated with a special corporate logo.
The article will consider the test of the well-known ZR magazine, carried out on SAE-5W30 oils, in conditions close to real ones, namely on brand new Ford Focus cars, just released from the factory.
Test conditions
All 5w-30 oils were tested under the same conditions.
Conditions under which 5w30 engine oils were tested:
- 10,000 km, of which idle - 54 hours,
- 100 hours at 6000 rpm, which included a city cycle in traffic jams, and 45 cold starts.
Moreover, it is worth paying attention to the fact that oil was constantly added to the cars, respectively, this casts doubt on the validity of testing.
Test results
As a result of the experiments, Castrol, G-Energy and Mobil were included in the top three. The entire table of contenders for the title of the best is formed below.
1. Castrol Magnatec A1 5W-30
Synthetic car oil 5W-30 - Castrol Magnatec A1.
The manufacturer has declared increased cleaning of engine parts for long-term action, based on molecular structure using Intelligent Molecules technology. The base of the oil is synthetics. Recommended for all types of modern engines.
Test indicators - for fumes, Castrol gave not bad indicators, but among the tested oils it turned out to be average, the iron residue in working out did not much exceed the norm, which speaks of good washing abilities only at the beginning, the residues in chemical. oxidation also exceeded the norms, so it is recommended to change the oil after 10000 km, for it this is a critical indicator.
2.G-Energy F Synth EC 5W-30
Synthetics by G-Energy F Synth EC.
Manufacturer's claim for super protection, both at low and high temperatures, thanks to a stable protective film. The feature of this oil for increased energy saving was highlighted, which implies use in Ford supernova engines (recommendations from Ford). The product is suitable for all types of engines and can be used on vans, jeeps and all types of passenger cars.
Testing - average values for viscosity change, not bad for iron content, fumes are normal - average oil from Gazprom, but of Italian origin. G-Energy F Synth EC is not designed for long runs without replacement, its stock of detergent reserves is very low.
3. Mobil Super FE Special 5W-30
Synthetic motor oil Mobil Super FE Special.
A loud application from the manufacturer - what exactly this engine oil belongs to the VIP class, and guarantees reliable and high-quality protection of the car engine at extreme loads over long distances. The base is a hydrocracking base. Application - supernova engines of passenger cars.
Test indicators - the oil really confirmed its excellent detergent properties, but took first place from the end in terms of fumes, so it cannot be called economical in any way. Further, the test showed a very high iron content during fusion, which is also not very good and the oil still needs to be changed after 10,000 without experimenting with long distances.
4. Motul 8100 Eco-nergy 5W-30
Synthetic oil Motul 8100 Eco-nergy.
A statement from a French manufacturer - economical, with excellent detergent and protective characteristics, with the presence of anti-wear effect, good anti-corrosion properties, stop foaming, antioxidant. The manufacturer recommends using the oil for all groups of cars A1 / B1 and A5 / B5 according to ACEA.
Tested - a good oil with all average performance, with stable average performance under medium loads, stable middle class.
5. Shell Helix Ultra Extra 5W-30
Motor synthetics Shell Helix Ultra Extra.
Presentation from the manufacturer - synthetic motor oil of the "Premium" class, with excellent detergent characteristics and full protection of all car parts. Economical in consumption, it can work on any engine under extreme loads with an extended drain interval. It has the eco characteristic of all Shell products due to its reduced chlorine content. Recognized by Mercedes Benz, VW and BMW. Ideal for modern diesel engines and legacy powertrains.
Testing - the oil showed the highest performance and fully corresponded to the declared one. The iron content is low, the waste is minimal, which confirms its operation without top-ups, the acid rate of mining is not high, the viscosity parameter is stable without coordination jumps, taking into account temperature changes.
6. THK Magnum Professional F 5W-30
Synthetic engine oil THK Magnum Professional F.
The manufacturer's application is a fully synthetic oil with good energy efficiency, focused on cars from Ford, as confirmed by the automaker. Stay-in-grade job characteristics. Indicated for use in gasoline engines (and with modifications turbocharging and direct injection) in passenger cars.
Test results - The oil showed itself very well, became a leader in terms of waste parameters, perfectly preserved the engine parts, since the iron content in the development was minimal, the alkaline number also changed within the permissible range (in Russia). An interesting product that is worth paying attention to, given its low cost, THK Magnum Professional F will clearly take first place.
7. Total Quartz 9000 Future fuel economy 5W-30
Synthetic oil for cars Total Quartz 9000 Future fuel economy.
All-season oil with stable characteristics, shown to work in all modes - city, highway, traffic jams. Provides good engine protection by preventing dirt and sludge from entering the engine. Economical, not designed for exceeding replacement distances, maximum 10,000 km.
Test - the oil did not pass the test even for 10,000, it had to be topped up every 4000 km. At the same time, its viscosity turned out to be very low, the oil thickened and formed lumps of soot.
8.ZIC XQ LS 5W-30
Synthetic oil ZIC XQ LS.
From the manufacturer - base for ZIC XQ LS YUBASE oil + additive package from Lubrizol, Infinium, Oronite (USA) using VHVI technology. These parameters guarantee low consumption of engine oil, perfect engine protection, exceptionally high cleaning performance, and an extended replacement cycle. Actually, we have already met such parameters when testing the ZIC XQ LS 5W40, then the oil proved to be excellent and practically became the leader.
The test data is resistant to burning, but does not keep the viscosity too large changes, the iron content in the working out is higher than the norm, which indicates poor engine protection, the base number also exceeded the permissible limits in the change. Why almost two identical products showed such different results is not clear, perhaps the reason is in the additives - thickeners, the content of which is higher in 5W40.
We took three fully synthetic imported motor oils with SAE 5W-30 viscosity from the leading manufacturers that occupy the lion's share of the domestic market - ExxonMobil, Shell and Castrol. To this trinity was added the not so common, but no less famous Motul oil.
How was it tested? On each of the oils, a specially prepared bench engine was rotated in specified modes for one hundred and twenty hours, while its characteristics were compared at various stages of testing. The engine is a domestic VAZ-21114 eight-valve with injection, with a modified control program and a piston oil cooling system.
Why is the engine not a foreign brand? Test conditions do not allow. The technique requires before and after testing to open the motor, measure, defect, photograph and weigh the parts. And modern non-nashen engines cannot be disassembled and assembled - the crankshaft cannot be removed there. More precisely, you can remove it, but putting it back is already prohibited.
After a fixed time, we took - three times - samples of the oil to assess the rate of its aging. Changes in the physicochemical parameters of the oil were monitored, as well as the content of wear products in it. And opening the engine clarified the idea of deposits and wear.
To weed out doubts about possible fakes, we sent fresh samples of oils to the laboratory to determine the basic physical and chemical parameters and compared them with the indicated manufacturers. If they match, then the oils are real, not fake. Another thing surprised me: the initial parameters of all four oils are almost the same. Are they from the same barrel? From different! This became clear after measuring the dynamic viscosity over the entire temperature range. But first, let's remember what viscosities are in general.
KINEMATIC, DYNAMIC AND HTHS
There is a direct relationship between oil viscosity, friction loss and wear rate of the friction unit. In classical hydrodynamics, two viscosity characteristics are distinguished - dynamic and kinematic. It is the dynamic viscosity of the oil that is important for the motor, since it takes into account the change in density with temperature. And kinematic viscosity is important for oilers; it can be accurately measured with a capillary viscometer. Previously, the viscosity parameters prescribed by the SAE class limited only the possible range of changes in the kinematic viscosity of the oil at a temperature of 100 ° C. This range for SAE 30 oils is 9.3-12.6 cSt; for SAE 40 oils it is wider than 12.6-16.3 cSt.
The SAE classification has now been extended with dynamic viscosity restrictions at 150 ° C. This is the so-called high-temperature viscosity HTHS (High-Temperature, High-Shear).
Previously, it was believed that SAE classification was sufficient for the selection of oil, and then it turned out that it was not enough. Oils from one group at operating temperatures can differ in viscosity by tens of percent, and this is essential for the operation of the motor. Therefore, an additional restriction was introduced.
Manufacturers of modern oils are guided by opposite priorities. For example, Shell claims the low viscosity of Helix Ultra, which results in low friction losses. And Motul has specially developed 8100 X ‑ clear FE, which has a high HTHS value. Who is right?
For the sake of completeness, let's go through all temperatures - from winter to quite operating modes, like in a fully warmed-up engine. The highest values of the high-temperature viscosity HTHS at the first test are with Motul 8100 X-clean FE, as promised by the manufacturer: 3.2 mPa · s versus 2.7 mPa · s for Mobil. Takeoff run - almost 20%! This means that this oil will reduce the load on the bearing by 20% - or will increase the pressure on the bearing by the same 20% without deteriorating its operating conditions. The price for this is the highest dynamic viscosities at low temperatures: 8330 mPa s for Motul oil versus 6220 mPa s for Mobil oil. This means that it will be more difficult to start a motor with Motul oil in the arctic and antarctic.
However, it is more interesting to trace the dynamics of changes in this parameter during the entire period of testing. Oils Mobil 1 ESP Formula and Motul 8100 X-clean FE for 120 hours of torture with a Russian engine and Russian (not the best, as everyone says) fuel changed their parameters slightly and quite predictably. During the tests, the dynamic viscosity in the entire temperature range increased by only 3-5%.
But Castrol Edge FST and Shell Helix Ultra oils have changed their viscosity by 21-28%! Moreover, the increase in the viscosity of Castrol oil began almost immediately - such a dynamics is not typical for the usual behavior of the oil. And Shell oil did a good job until the middle of the tests, but gave up in the second half of the cycle. As a result, by the end of the tests, the advantage that these oils had over Motul oil in terms of viscosity at low temperatures completely melted. Those planning to use these oils in the harsh northern conditions have something to think about.
An even more expressive picture, reflecting the rate of aging of oils, is given by the analysis of the dynamics of changes in the kinematic viscosity at 100 ° C.
And again: the viscosity of Motul oil is practically unchanged. For Mobil oil, the change in viscosity is more noticeable, and by the end of the test period it reached the threshold value. Castrol, on the other hand, showed a very significant increase in viscosity at 100 ° C, well beyond the acceptable range. The most interesting thing is that the viscosity at 40 ° C began to decrease by the end of the tests - this can be seen from the data in the final table. The viscosity index flew as much as 210!
Viscosity index is an important parameter of engine oil, which characterizes the rate of change in viscosity with increasing temperature. The higher it is, the smaller the difference between the viscosities at high and low temperatures. For full synthetics, it usually lies in the 160-180 range.
And one more oddity of Castrol oil. Typically, the base number gradually decreases: a complex of detergent additives is triggered. And here on the contrary - growth!
It is possible that calcium or another element returns to the oil from deposits formed in the engine, to which the device reacts. By the way, for the other three oils, the same method gave the expected result.
We evaluated the energy saving of oils twice, comparing in the modes of our cycle both with fresh oil and with 120 operating hours. These results are also tabulated.
Here again it is appropriate to return to the conversation about HTHS. The oil with the highest HTHS value - Motul 8100 X ‑ clean FE - also performed better here. However, all tested oils, judging by the results, may well be classified as energy-saving. But those with a lower viscosity growth rate changed the fuel consumption and engine power the least after a cycle of long tests. The effect of high-temperature viscosity was most clearly manifested in the analysis of the protective functions of the oil. Analysis of the content of wear products in oil samples taken at the final stage of testing clearly reveals the unconditional leadership of oil with high HTHS. This is the Motul 8100 X-clean FE. It is quite understandable: the higher the viscosity, the greater the thickness of the separating layer and less.
Autopsy of the engine after test cycles showed approximately the same final level of high and low temperature deposits, with more stable oils giving slightly better results. But in general, all oils in these parameters showed a high result, characteristic of high-quality synthetics.
NOT FOR RUSSIA?
Why did the oils perform differently during the tests? Two of them - Motul 8100 X ‑ clear FE and Mobil 1 ESP Formula - worked without remarks, while the other two showed less optimistic results. The very nature of oil aging, when the viscosity begins to walk, and other parameters generally remain normal, most often indicates that the additives included in the used additive package conflict with something.
In starting this expertise, we wanted to continue the theme of the “oil plague” that we raised three years ago - the unpredictable decomposition of oil, in which black tar is formed in the channels of the lubrication system, the oil pan, and the valve mechanism. This disease has killed more than one hundred motors. And the oilmen named Russian gasoline as one of the possible culprits of this trouble. Then we found other causes of the "plague", moreover, confirmed by experiment. But it was also necessary to check the version about the influence of bad gasoline.
The solution was found after our examination of cheap 95 gasolines (ZR, 2015, No. 5), during which it turned out that most of them contain prohibited methanol. This is the kind of gasoline we used for our tests.
Thus, our research has confirmed that bad gasoline can really spoil the oil, and with it the engine. Yes, but Motul 8100 X-Сlean FE and Mobil 1 ESP Formula oils, working on the same gasoline, did not make any complaints about it! This means that the additive package can be adjusted in such a way that the oil works normally under our conditions. Another thing is that not everyone succeeds.
In the meantime, we repeat: go around unverified gas stations in a wide circle! When it comes to choosing an engine oil, we advise you to go for products with a higher HTHS value.
The motor, nerves and wallet will be more whole!
