What viscosity to pour engine oil in summer
Motor oils for summer
Content
The other side of the coin is an increase in temperature loads, especially in traffic jams, off-road conditions and with aggressive driving style. In such hot conditions there is a risk of overheating. This requires motor oil to provide increased reliability of engine protection, maintain viscosity not lower than the maximum permissible, as well as effectively counteract the oxidation and destruction of the base oil and additive package.
The use of modern technologies for purifying the mineral base and producing synthetic base oils gives ROLF Lubricants GmbH the opportunity to produce high-quality summer and all-season oils in both the budget and premium segments. The ROLF brand line allows you to choose motor oil for an old car, a modern budget sedan, a heavy SUV or a sports car with a forced engine, as well as for trucks and special equipment.
Oil change intervals in summer
When producing ROLF motor oils, their characteristics not only meet the requirements of the declared quality classes and manufacturer approvals, but also exceed them with a margin sufficient for long-term operation of the product. However, increasing the replacement period established by the car manufacturer is not recommended.
The fact is that replacement intervals are set by factories so that after their expiration the oil does not “go to zero”, but retains a sufficient level of protective properties, and the viscosity does not exceed the requirements of the standard. The quality of engine oil is one of the main factors affecting engine life. It is impossible to independently determine the timing when the oil will “use up”, if they are not indicated in the service book, without laboratory tests. Therefore, when choosing ROLF products, follow the intervals recommended by the manufacturer.
Summer oil viscosity
The SAE standard defines the viscosity of summer oils in symbolic classes with digital indices from SAE 20 to SAE 60. The higher the index, the higher the kinematic viscosity of the oil. In addition, the minimum dynamic viscosity at elevated temperatures is also standardized. This allows us to guarantee the preservation of oil performance under increased thermal loads on a water-cooled engine.
The engine oil must be filled with the same viscosity grade as indicated in the service book. A more viscous material will splatter less easily. First of all, this will affect the quality of lubrication of the cylinder walls. A less viscous lubricant carries the risk of reducing pressure in the lubrication system, deteriorating the performance of hydraulic compensators, and phase shifter clutches. The use of oil with a lower SAE viscosity class is not permitted. More viscous oil can be used in summer only in two cases:
- the engine is operated in hot climates, with the risk of overheating, under heavy loads on the vehicle itself (off-road, transportation of heavy loads);
- the engine is forced, which inevitably leads to a more severe temperature regime for its operation.
When using all-season oils in the summer as the most convenient to use, one nuance must be taken into account. For popular all-season “forty” oils (with SAE index 40), the standard defines the requirements for high-temperature HTHS viscosity and, depending on the winter viscosity class:
- for oils 0W-40, 5W-40, 10W-40 – no less than 3.5 mPa*s;
- for oils 15W-40, 20W-40, 25W-40 – no less than 3.7 mPa*s.
That is, replacing the 15W-40 oil recommended by the manufacturer with 5W-40, although it will be useful in the winter, in the summer it may lead to a decrease in viscosity below that included in the engine design, even if only slightly.
Types of summer oils
The most advanced oils that meet the extremely stringent requirements for engine protection and the environment are synthetic-based oils. ROLF Lubricants GmbH uses three types of synthetic base oils:
- hydrocracking synthetics . These are the most affordable varieties based on natural oil. However, unlike the classic “mineral water”, the raw materials are heavier fractions, the carbon chains of which are destroyed and saturated with hydrogen. The quality of such oil is higher than that of mineral oil, while the cost of production is low;
- polyalphaolefin (PAO) synthetics . On the contrary, it is produced from light gaseous fractions through controlled synthesis. Such oils have excellent viscosity stability, oxidation resistance and long service life. The high purity of the feedstock, devoid of sulfur compounds (which make up a particularly large proportion of heavy grades of oil), is an additional advantage of oils in this group;
- synthetics based on alkylated naphthalenes . It has excellent lubricity, stability under high thermal loads, and is reliably held on the metal surface. At the same time, it is cheaper than ester due to more accessible raw materials.
ROLF semi-synthetic for summer operation combines the high quality of hydrocracking oils with the availability of mineral ones. On vehicles that do not have strict requirements for the quality and characteristic properties of lubricants (for example, standardized ash content for engines with particulate filters), it can be confidently used as an economical replacement for oils recommended by the manufacturer, subject to the factory requirements for quality class, viscosity and specific tolerances .
The technologies of ROLF Lubricants GmbH, used in the production of mineral motor oils, perfectly illustrate one fact: the ROLF OPTIMA 20W-50 mineral oil in terms of performance properties is certified to comply with the API SL/CF quality class, which was initially presented only in the synthetic lines of the largest manufacturers.
ROLF motor oils for summer
ROLF 3-SYNTHETIC 5W-30
A unique feature of this summer motor oil is the combination of three synthetic bases, which allows it to have properties corresponding to premium-class products at an attractive price for a wide range of motorists. Excellent protection, starting from the first revolutions, due to ease of pumping, good retention of the oil film after stopping the engine, and ending with moments of maximum load, makes it an excellent choice for modern high-performance engines.
ROLF GT SAE 0W-40
Polyalphaolefin oil reliably protects the engine from wear both on a July afternoon and in the morning in February. Due to its high alkaline number, it is well compatible with Russian fuels that have a high content of sulfur compounds. Allows replacement intervals to be extended in accordance with BMW approval LL-01.
ROLF Energy 10W-40 SL/CF
A semi-synthetic with a high viscosity index, balanced in terms of price and quality, maintaining good protective properties in the most severe operating conditions: under high loads and aggressive driving, in summer traffic jams. A modern package of detergent additives keeps the engine clean throughout many oil change cycles.
ROLF Dynamic 10W-40 SJ/CF
Budget-friendly semi-synthetic oil for used gasoline and diesel cars, whose owners want to preserve maximum engine life. It has low waste consumption, creates a strong oil film on the cylinder walls and in the most loaded friction pairs. Stabilizes pressure in the lubrication system.
ROLF OPTIMA 15W-40 SL/CF
Mineral based oil with high performance characteristics. Compatible with gasoline and diesel engines, including those equipped with compressors and turbines. It cleans the engine well of old deposits and prevents the formation of new ones.
ROLF JP SAE 0W-20 ILSAC GF-5 API SN
Low-viscosity synthetic oil designed for engines of Japanese, European and American cars that require the use of only energy-saving lubricants with the ILSAC GF-5 specification. Compatible with all types of catalysts, ensures minimal waste consumption through piston rings and crankcase ventilation.
avtoexperts.ru
The main parameter when choosing motor oil is its viscosity. Many car enthusiasts have heard this term, seen it on the labels of oil cans, but not everyone knows what the numbers and letters depicted there mean, and why this process fluid with a certain degree of viscosity needs to be used on a certain engine. Today we will reveal the secrets of motor oil viscosity.
First of all, let's determine the significance of the oil viscosity degree for the engine. An engine has many parts that come into contact with each other during operation. In a “dry” engine, the operation of such parts will not last long, since due to mutual friction they wear out and fail relatively quickly. Therefore, motor oil is poured into the engine - a technical fluid that covers all rubbing parts with an oil film and protects them from friction and wear. Each oil has its own degree of viscosity - that is, the state in which the oil remains liquid enough to perform its main function (lubricating the working parts of the engine). As is known, unlike coolant, the temperature of which is always stable during driving and is at the level of 85-90 degrees, engine oil is more susceptible to external and internal temperatures, the fluctuations of which are quite significant (under some operating conditions, the oil in the engine heats up to 150 degrees).
To avoid boiling of the oil, which could cause damage to the car’s engine, specialists in the manufacture of this technical fluid determine its viscosity - that is, the ability to remain in working order when exposed to critical temperatures. For the first time, oil viscosity grades were determined by specialists from the American Association of Automotive Engineers (SAE). It is this abbreviation that appears on oil packages. Following it are numbers separated by the Latin letter W (it means the engine oil is adaptable to working at low temperatures) - for example, 10W-40.
In this series of numbers, 10W denotes low-temperature viscosity - the temperature threshold at which a car engine filled with this oil can start “cold” and the oil pump will pump the technical fluid without the threat of dry friction of engine parts. In the above example, the minimum temperature is “-30” (subtract 40 from the number in front of the letter W), while subtracting 35 from the number 10, we get “-25” - this is the so-called critical temperature at which the starter can crank the engine and start. At this temperature, the oil becomes thick, but its viscosity is still sufficient to lubricate the rubbing parts of the engine. Thus, the larger the number in front of the letter W, the lower the sub-zero temperature the oil will be able to pass through the pump and provide “support” to the starter. If there is a 0 in front of the letter W, this means that the oil will be pumped through the pump at a temperature of “-40”, and the starter will crank the engine at the lowest possible temperature of “-35” - naturally, taking into account the viability of the battery and the serviceability of the starter.
The number “40” after the letter W in our example indicates high-temperature viscosity - a parameter that determines the minimum and maximum viscosity of the oil at its operating temperatures (from 100 to 150 degrees). It is believed that the higher the number after the letter W, the higher the viscosity of the engine oil at the specified operating temperatures. Exact information about the high-temperature viscosity of oil required for a particular engine is exclusively available to the vehicle manufacturer. So we recommend that you follow the car manufacturer’s requirements for motor oils, which are usually indicated in the owner’s manual.
The degree of viscosity of the oil is determined according to the accepted international nomenclature SAE J300, in which oils are divided into three types according to the degree of viscosity: winter, summer and all-season. According to the degree of viscosity, winter oils include liquids with parameters SAE 0W, SAE 5W, SAE 10W, SAE 15W, SAE 20W. Summer oils in terms of viscosity include liquids with parameters SAE 20, SAE 30, SAE 40, SAE 50, SAE 60. Finally, the most common oils in terms of viscosity today include all-season oils - SAE 0W-30, SAE 0W-40, SAE 5W-30, SAE 5W-40, SAE 10W-30, SAE 10W-40, SAE 15W-40, SAE 20W-40. They are the most practical of all, since their temperature parameters are optimally balanced for use at various critical temperatures.
To select an oil with the optimal viscosity degree for your engine, you need to follow two rules.
1. Selecting the degree of oil viscosity according to climatic conditions. It is no secret that oil with the same viscosity level (for example, SAE 0W-40) will behave differently when the car is operated in a region of the country with a hot or, on the contrary, cold climate. Therefore, when selecting oil, you need to remember that the higher the air temperature in the region in which the car is operated, the higher the viscosity class of the motor oil should be, which can be determined by the number in front of the letter W. This is what the temperature conditions at which it is recommended to use oil with varying degrees of viscosity:
SAE 0W-30 - from -30° to +20°C;
SAE 0W-40 - from -30° to +35°C;
SAE 5W-30 - from -25° to +20°C;
SAE 5W-40 - from -25° to +35°C;
SAE 10W-30 - from -20° to +30°C;
SAE 10W-40 - from -20° to +35°C;
SAE 15W-40 - from -15° to +45°C;
SAE 20W-40 - from -10° to +45°C.
2. Selecting the degree of oil viscosity according to the service life of the engine. The older the car, the more its rubbing pairs wear out - parts that come into contact with each other during the operation of the power unit, and the gaps between them increase. Accordingly, in order for these parts to continue to perform their functions, it is necessary that the oil film on their surfaces be more viscous. That is, for engines that have exhausted half of their service life, it is necessary to buy oils with a higher degree of viscosity, and for new ones - with a lower one.
Is it possible to fill in 5w30 engine oil in summer?
Oil 5w30 and 5w40: main differences and which one is better to choose
The large number of products and diversity on the fuel and lubricants market has recently been the main reason why selecting motor oil involves certain difficulties. Car enthusiasts constantly focus attention not only on quality, but also on issues of seasonality, mixing, compatibility and interchangeability of oils of different 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 the lubricant (synthetics, semi-synthetics, mineral oil). In other words, the quality and price of the product will depend on the base and additive package. As for 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 advisability of operating an internal combustion engine on a product with one or another viscosity.
In this article we intend to talk about the popular 5w30 and 5w40 oils, 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 also which oil is better, 5w30 or 5w40 in winter and summer.
Viscosity and seasonality of motor oil
Let's start with the fact that many drivers have heard and some have encountered a situation where in winter the engine cannot be started due to the fact that the lubricant has become very thick in the crankcase. This means that with a charged battery and a fully functional starter, it is still not possible to crank the crankshaft at the required frequency, which is necessary to start the internal combustion engine.
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 between summer and winter products.
The entire modern classification of oils comes down to the fact that the driver can choose a product from catalogs of all-season motor oil.
Such lubricants have different viscosities, tolerances, base stocks and additive packages. Moreover, recently the use of universal oil, which can be equally poured into both gasoline and diesel engines, has become increasingly practiced. So, let's return to the conditional classification by season:
- Without going into details, the so-called summer lubricant has a high viscosity 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 surfaces from wear.
- Winter lubricant has a low viscosity; this lubricant allows you to start the engine in severe frosts without much difficulty. However, a more “liquid” low-viscosity substance forms a thin protective film after warming up the internal combustion engine, inferior in quality to engine protection compared to its summer counterparts.
- All-season engine oil, unlike winter and summer, does not require seasonal replacement, that is, it does not need to be changed seasonally and can be used year-round. Taking into account the fact that almost all modern products are all-season, such products represent the optimal balance, combining the necessary properties for summer and at the same time suitable for winter use
In order to separate lubricants based on the dependence of viscosity on temperature, there is a special classification according to SAE (a specification that was developed by the Society of Automobile Engineers). The SAE classifier defines summer products as ranging from 20 to 60. Winter lubricants are rating from 0W or 5W to 25W.
The combination of these two indicators is separately indicated on all-season oil and is well known to car enthusiasts (for example, oil 0W20, 5W30, 10W40, etc.). Now let's figure out what the viscosity of the popular oils 5w30 and 5w40 is, as well as what exactly the decoding of 5w30 and 5w40 oils will mean. Let us add that the topic of choosing 5w30 or 5w40 oil for a diesel engine requires the same answers to the questions posed in this article.
What is the difference between 5w30 and 5w40 engine oil?
In order to accurately determine the viscosity of an all-season lubricant in winter and summer, you need to look at the numbers before and after the letter W in the designation. The indicated letter is an abbreviation for Winter. For example, 5W30 means that 5W indicates the SAE viscosity grade at subzero temperatures.
The number 30 is the SAE temperature rating in relation to the product's properties at high temperatures. These two specifications will determine both the ease of starting, fluidity and pumpability of unheated lubricant in winter, and the stability of the protective film on the surface of loaded parts at maximum temperatures.
If you ask yourself how 5w40 oil differs from 5w30, then it should be noted that these oils have identical indicators that characterize their suitability for use in winter. The 5W classification clearly indicates that this oil ensures reliable starting of the internal combustion engine down to -30 degrees below zero.
Now let's take a look at the SAE high-temperature viscosity, that is, the difference between 5w30 and 5w40. A general comparative analysis of the data indicates that the kinematic viscosity of 5W30 when heated to 100 degrees Celsius ranges from 9.3 to 12.5 mm sq./sec. At the same time, 5W40 under similar conditions has a viscosity index from 12.5 to 16.3 mm sq./sec.
From this comparison it is also clear that the minimum HTHS viscosity in the case of 5W30 is 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-heat conditions, 5W40 is noticeably different from its 5W30 counterpart in terms of high-temperature viscosity. Otherwise, the answer to the frequent question of which oil is thicker, 5W40 or 5W30, will be 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 compared to its competitor. As it may seem at first glance, such a product is no different during winter operation and better protects the engine 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 engine manufacturers. The fact is that even a slight increase in oil viscosity in some units can lead to worse pumpability, that is, lubricant will not reach the friction pairs in the required quantity.
Also, when choosing a summer viscosity value, you should take into account the fact that too “thin” lubricant (for example, 5w30) can lead to lubricant leaks through oil seals, gaskets and other seals. The oil film on parts when using low-viscosity oils may turn out to be thin, as a result of which the wear of components significantly increases and the temperature of the internal combustion engine increases. In other words, before choosing 5W40 or 5W30, you must:
- Separately, make sure that both types of oil are on the list recommended by the manufacturer for a particular engine.
- It would also be a good idea to take into account the operating features of the engine.
For example, a viscosity index of 30 means that the declared characteristics of the motor 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 the summer, while the driver constantly “turns” the engine to high speeds, 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 5w30 and 5w40 oils
Quite often, especially in the event of an emergency malfunction, it becomes necessary to add oil to the engine. In such a situation, the lubricant of the same manufacturer whose product was originally poured into the power unit is not always at hand.
The same is true for the viscosity index. For this reason, it is important to know whether 5w30 and 5w40 oil 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 semi-synthetics 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, mixing oils from different manufacturers is allowed, but only if it is taken into account that they have the same basic base.
This means that mineral oil is mixed only with mineral oil, semi-synthetic oil with a similar product, etc. At the same time, it is still impossible 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 eliminating the breakdown, you must immediately drain such mixed lubricant from the engine and change the oil filter. Also, in some cases, it may be necessary to additionally flush the engine before changing the oil.
Let's sum it up
Taking into account 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 engine manufacturer. At the same time, you should pay attention to the base, since a more expensive semi-synthetic oil, for example 5W40, will be better in 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 production of fuels and lubricants. This means that the information regarding lubricants in the instruction manual may be very out of date.
Moreover, if you have to select the lubricant yourself, you need to take into account a number of features that we described above. To put it simply, expensive low-viscosity synthetics will not always mean that an old engine using such a 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 ground, and also take into account the individual characteristics of the operation of the internal combustion engine. This means that the lubricant should not dilute greatly and lose its properties, taking into account the maximum possible heating, and also remain fluid with the onset of cold weather.
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Motor oils and everything you need to know about motor oils
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What viscosity oil should be poured into the engine in summer?
The lubricants market does not suffer from a shortage of motor oils from Russian and foreign brands. Motor fluids are usually divided into three volume groups for use in gasoline engines; in diesel; in both (universal).
Choosing engine oil for the summer
The lubricant is selected based on summer temperatures and viscosity parameters. It is also recommended to pay attention to the operating conditions of the vehicle. To understand this issue, let’s analyze the technical characteristics and properties of motor oils.
Lubricants are traditionally divided into summer and winter according to the parameters of viscosity and dilution when heated in the internal combustion engine system. Summer lubricants must have higher viscosity to protect engine mechanisms from friction and further wear.
These products include motor fluids with SAE viscosity classes from 20 to 60. Digital gauges display the degree of viscosity. The higher the number, the higher the viscosity index of the summer oil.
Temperature conditions
First of all, it is necessary to pay attention to temperature indicators and fluctuations for a particular climate zone. The colder the average climate/weather, the lower the viscosity readings should be.
Motor oils with indexes 0w30, 0w40 ensure quick start of the internal combustion engine in severe frosts due to easy cranking of the crankshaft. They are pumped through the system quite quickly, which allows the pump to increase the pressure level depending on the loaded mechanisms of the power unit.
This increases the service life of the car engine. Oils with the lowest viscosity index minimize friction and mechanical losses, thereby saving fuel consumption.
However, low-viscosity liquids become fluid under high-temperature conditions. This is especially true in hot weather, when at temperatures above 30°C the lubricant becomes more liquid and the protective microfilm is destroyed. Therefore, experienced car owners use a more viscous motor oil for the internal combustion engine system: 15w40, 10w40, 5w40, 20w40.
Tolerances from car manufacturers and oil viscosity
Vehicle manufacturers use different tolerances for motor lubricants. When choosing a summer car oil, it is recommended to analyze the tolerances for a specific car brand. Let's start from conditional tolerances and at the same time consider the temperature ranges for using summer, out-of-season oils.
For example, for the power unit, the manufacturer recommends using all-season fluid with a viscosity class of 5w30 from -25C° to +25C°. In the summer, it is recommended to use 5w40 lubricant, and when the weather is hot outside, more than 40°C, use 10w40, 15w30 or 20w40.
As a rule, car enthusiasts prefer to use a more viscous oil to reduce wear on the internal combustion engine system. Experienced car owners are familiar with the fact that as the engine wears out, the gaps in the friction pairs increase.
To compensate for microcracks and gaps, as well as to reduce extraneous noise, in the summer it is recommended to fill in oils with a high degree of viscosity - 10w40, 20w40, 15w30. Due to this, the pressure in the oil system is stabilized and its service life is increased.
In summer, internal combustion engine mechanisms are subject to strong heating. The friction force between parts increases, which leads to wear. Therefore, it is recommended to use more viscous motor lubricants.
In addition, some car enthusiasts prefer to drive fast. The engine begins to spin up after 100-150 thousand kilometers, so it is recommended to switch from universal lubricant 5w30 to 5w40 or 10w40. If the engine is in a worn condition, then it is optimal to use lubricants with a viscosity index of 15w40 and 20w40.
What oil to fill in for the winter: 3 selection criteria
The appropriate quality group is indicated in the booklet with the description of your car. However, everything is simple here: if you choose the SN designation, you can’t go wrong, because it is a priori better than the earlier SL and SM oils. Of course, reverse replacement is unacceptable.
Viscosity is a little more complicated. The smaller the first number in designations like 0W-40 or 5W-30, the lower the temperature for which the oil is designed. And if “zero” comes first in the designation, then this is the most frost-resistant product today.
SAE requirements for low-temperature viscosity of motor oils
Low temperature viscosity
(maximum viscosity, mPa s, at temperature, °C)
60000 at – 40 °C
60000 at – 35 °C
60000 at – 30 °C
60000 at – 25 °C
60000 at – 20 °C
13000 at – 10 °C
60000 at – 15 °C
However, an interesting question arises here. Which oil will provide easier starting in cold weather - 0W-30 or 0W-40? In both cases there is a “zero” in front, but do these oils really behave exactly the same in the cold? Formally, we know that the second digits in the designation indicate the permissible range of changes in oil viscosity at 100 ºС, but don’t they indirectly affect the “frost” properties?
Imagine the influence! We conducted a similar experiment designed to answer the question: is the real low-temperature viscosity different for different “nulls”? And - most importantly! – which oil will provide an easier cold start: 0W-30 or 0W-40?
For testing, we used a ball viscometer, which allows us to determine the time of fall of identical steel balls in calibrated glass tubes filled with the motor oils being tested. For the purity of the experiment, we took four duets of the same name: Shell, Castrol, Bardahl and Mobil. At the same time, Castrol was compared with Castrol, Shell with Shell, etc. So: in all measurements, the low-temperature viscosity of 0W-30 oils turned out to be lower than in the same 0W-40! In this case, the gain ranged from 7 to 15%.
What does the theory say? And she says that our result does not contradict science. If we evaluate the absolute values of low-temperature viscosity for oils of class 0W-30 and 0W-40, then the margin to extreme values for oil of class 0W-30 is, as a rule, greater. And if the engine manufacturer does not object, then to facilitate cold starts it makes sense to fill in thirty instead of forty. By the way, in this case there is an expected gain in efficiency: when warming up, the higher the viscosity, the greater the friction losses, and therefore more fuel will have to be burned.
What's in a name?
By the way, when choosing a brand, it’s a good idea to familiarize yourself with the recommendations of automakers. Inscriptions such as FIAT, Porsche or VW often flash on the canisters, but here you need to read more carefully. If the text uses the word Meets (or the Russian “Complies”) - for example, “Meets: VW”, then this means only one thing: the oil manufacturer believes that its product fully meets the requirements of VW. This can generally be regarded as an advertising statement. But the term Approved, for example - MB Approval 229.1 says that the car manufacturer (in this case we are talking about Mercedes) tested this oil and officially approved its use in their cars. This is easy to check: you need to go to the official website of the car manufacturer and find out whether, for example, FIAT gave approval to Pupkov Oil oils. At the same time, you can clarify a bunch of details: many oil manufacturers, having received approval for one product, seem to accidentally declare that their entire line of products has been approved.
Happy travels and trouble-free cold starts!
