Any modern car can not do without oil, which, in addition to the engine, is also poured into the transmission. There is a whole variety of this consumable on the market and there is a whole viscosity table for motor oils. The viscosity designation in it makes it possible to easily select the composition necessary for your vehicle. You only need to be well versed in such an indicator as viscosity.
What it is? Why is viscosity so important? And in general, what important role does oil play in the engine or transmission elements? Answers to these and other questions will be presented in this article.
The importance of the presence of oil in the engine can hardly be overestimated, since it is entrusted with the most crucial task - to reduce the friction of the surfaces of parts. Unfortunately, not all drivers attach importance to this. There are those who forget about oil in general, and then, in the end, the engine completely fails due to significant damage.
However, motor oil has another equally important property, depending on the viscosity index. The fact is that thanks to oil lubrication, the antifreeze performance is noticeably improved, and this prevents the engine from overheating.
During engine operation, mechanical and thermal processes constantly occur in it, due to which it can undergo overheating. Thanks to the circulation of engine oil, which gets to many details, the excess heat is removed from the power plant in an efficient manner. At the same time, it is distributed between all the surfaces to which it enters.
But, in addition to removing heat and reducing friction, engine oil collects various “garbage”. As a result of friction of parts, metal dust is formed, which on some car models looks like chips. Circulating through the engine, the oil, due to its viscosity, collects this dust, which then settles in the filter.
According to the viscosity table, the performance depends on the kinematic viscosity. Therefore, it is worth exploring this characteristic in more detail.
We all heard that the oil has a viscosity, but not everyone understands that this is specific. Under this definition, the main indicator of the quality of the consumable can be considered. In other words, viscosity is the ability to maintain its fluid properties under the influence of temperature changes. That is, from the lowest rates in the winter to the highest values \u200b\u200bin the summer, with maximum engine loads.
Moreover, the value is not constant, but temporary in nature and depends on a number of factors, including:
In all countries of the world, without exception, a single oil was introduced - SAE J300, which can be presented in the form of a table of viscosity of motor oils. The first three letters are the designation of the American Society of Automotive Engineers. In English it looks like this: Society of Automotive Engineers.
According to this system, the conventional units that mark one or another brand indicate the degree of viscosity according to SAE VG (Viscosity Grade). It is worth considering in more detail how exactly the consumable is divided.
There are two concepts of engine oil viscosity:
Kinematic viscosity is the ability of an oil to maintain its fluidity under normal or high temperature conditions. In this case, 40 ° C is considered the norm, and increased - 100 ° C. To measure the kinematic viscosity of engine oil, special units are used - centistokes.
At dynamic or absolute viscosity, there is no dependence on the density of the consumable itself. Here, the resistance force of two layers of oil located at a distance of a centimeter and moving at a speed of 1 cm / s is taken into account. The measurement is carried out using special equipment - a rotational viscometer. The device is able to recreate the operation of engine oil in conditions as close as possible to real ones.
Depending on the degree of yield index, there are 12 classes of lubricants in total. Moreover, all liquids belong to winter and summer grades (6 classes, respectively). Each marking has a digital or alphanumeric designation (or viscosity index).
By and large, any oil is able to work under any conditions. However, for SAE indicators, an important role is given to the lower temperature limit. Oils with the prefix W to the index (from the word winter - winter) have the lowest possible temperature threshold for pumpability. This means that starting the engine in winter (in especially frosty conditions) will be safe.
All-season motor oils are awarded a separate classification. According to SAE they have a double designation. That is, the kinematic viscosity value is first indicated during successful tests at the lowest temperature possible. The second value, as can already be understood, is at its maximum.
Some manufacturers use the letter W to designate certain oils. So you can immediately guess that this is winter motor oil. All six classes are labeled as follows:
If you need to find out at what negative temperature the car will start successfully, you should subtract 40 from the designation in front of the letter W. For example, you are interested in oil under the index SAE 10W. After easy calculation, we get the desired value of -30 ° C.
That is, a special viscosity table can not even be used. Although for reliability it does not hurt to make sure the right choice.
In the classification of oils by SAE, summer consumables do not have any letters in the designation, it is understandable. And their classes in the table already look like this:
The higher the index, the higher the viscosity index of the oil. That is, for a hot climate, it has a thicker consistency. For this reason, such oils must not be used at ambient temperatures below 0 ° C. Due to their viscosity, they best show their properties only in the summer heat.
Combine all the properties of winter and summer oils. Therefore, they also have a joint designation, separated by a dash. For example:
The use of a different designation for all-season oils is not allowed (SAE 10w / 40 or SAE 10w / 40).
It is this type of consumable that has received the greatest distribution among most drivers, due to the special viscosity class of engine oil. There is no need to change the oil twice a season. However, multigrade oil is suitable only for those who live in the middle lane, where the climate is more favorable.
Typically, car manufacturers for each engine select individual indicators of fluidity of the oil. This allows you to increase the efficiency of the engine with minimal wear. For this reason, it is worth adhering to the recommendations of the automaker with respect to each specific model. And the advice of acquaintances and friends, especially strangers, which are employees of the service station, it is better not to take for the truth.
However, there will never be a limit to human curiosity. What can happen if you use “inappropriate” engine oil? There are two possible outcomes:
In this regard, it is necessary to choose the right oil for your car in order to avoid serious consequences. The main thing is that the viscosity corresponds to the conditions under which the car is operated.
Unfortunately, not all drivers prefer to choose a lubricant according to the SAE oil classification. Two major errors are popular among them. Fans of fast driving refuse standard lubrication and prefer sports varieties. However, this is a sure-fire way to bring your car’s engine to its deathbed. This is the first mistake.
Others hold a second erroneous opinion. According to owners of old cars, at that time there was still no good engine oil that would fully satisfy the needs of the "old ladies". Most of them are already set up for major repairs.
This is fundamentally wrong, since at each stage of improving the technology of automobile production, at the same time, the development of a suitable engine oil was carried out. Two concepts (engine and oil) are, as it were, a single whole, and it is unacceptable to separate them.
In addition, many compounds in addition to the oil component had various additives of synthetic origin. Therefore, the experience of the vehicle here does not matter.
The table is compiled for a reason, because it is thanks to it that you can choose the necessary lubricant for a longer and more efficient engine operation. It should be remembered that the engine needs not only regular maintenance, but also the timely replacement of all consumables, including lubricants.
Chevron RPM Synthetic Transmission Fluid
MCP Transmission Fluid
SAE 50
ADVANTAGES
Chevron RPM® Synthetic Transmission Fluid Transmission Fluid has the following properties that provide added value to consumers:
Increased resistance to high temperatures and oxidation - a synthetic oil-based base oil, which is part of this transmission fluid, provides its exceptional stability;
. High viscosity index and low pour point - Excellent persistent properties of the synthetic base oil make it possible to use transmission fluid in a wider range of operating temperatures compared to mineral fluids.
PROPERTIES
Chevron RPM® Synthetic Transmission Transmission Fluid is specifically formulated for use in large trucks. It contains synthesized hydrocarbon base oil, which has excellent resistance to oxidation and high temperatures, a high viscosity index and a very low pour point. This product also has exceptional shear resistance even when operating under very severe conditions.
Due to its low pour point and exceptional fluid pumpability, even at very low temperatures, Chevron RPM Synthetic retains excellent lubricity even when operating at low temperatures, while the increased viscosity index provides excellent lubricity at high operating temperatures. Due to the resistance of the oil film to friction and foaming due to the low viscosity of the crude oil from which the base oil is synthesized, this transmission fluid can be used at lower temperatures than conventional mineral-based lubricants.
APPLICATION
Chevron RPM Synthetic transmission fluid, with improved pumpability at low temperatures and a high viscosity index, can be used in any climate zone and at any time of the year. The use of this product facilitates gear changes even at very low temperatures and reduces wear when starting the engine and shifting gears.
Chevron RPM Synthetic Transmission Transmission Fluid:
Meets the requirements of:
. Company Specifications Rockwell international" № 081;
. Company Specifications Eaton transmission division"No. PS 164.
Approved for use under the warranty on 750000 mil.
Approved for use in:
. transmission systems " Eaton roadranger";
. transmission systems " Meritor"(Rockwell companies).
TYPICAL TEST DATA
Type test average. In normal manufacturing, small deviations are possible that do not affect the characteristics of the product.
STORAGE
All packages must be stored under a canopy. For unavoidable storage in the open, barrels should be laid horizontally to prevent rainwater from entering and rinsing markings off barrels. Food should not be stored at temperatures above 60 C, exposed to direct sunlight or freezing. Information on health, safety and environmental protection is contained in the information sheet on the safety of materials. It describes in detail the potential hazards, gives warnings and measures for first aid, and also contains information on the environmental impact and methods of disposal of waste products.
Limitation of liability: Chevron Corporation declines all responsibility for any loss or damage incurred as a result of using this product for purposes other than those intentionally indicated in the lubricant passport.
Safety, storage, health and the environment: According to the information currently available, this product does not have a negative impact on health, provided that it is used for the purpose for which it was intended and in accordance with the recommendations indicated in the Safety Data Sheet of this product. You can get Material Safety Data Sheets at your local sales office or online. This product should only be used for the purpose for which it was intended. This product must be disposed of in an environmentally friendly manner and in accordance with local laws.
Reference:
| VISCOSITY is a property of a fluid that determines its fluidity and the higher the viscosity, the thicker the liquid (the less its fluidity, the greater its viscosity). When the engine is cold, the oil tends to thicken. In this case, it is important that it remains liquid even at low temperatures in order to flow through the engine, protect its parts and facilitate start-up. The lower the viscosity, the more oil will retain its fluidity in cold weather or when starting the engine. VISCOSITY INDEX - the dependence of the change in viscosity of oil on temperature ( the higher the viscosity index, the better the oil and the lower the viscosity of the oil depending on temperature). An oil with a higher viscosity index has better fluidity at low temperature (starting a cold engine) and higher viscosity at the operating temperature of the engine. |
OIL VISCOSITY - This is the main indicator of quality, which is common to all oils. The ambient temperature range in which this oil enables the engine to start without preheating, unimpeded pumping of oil by the pump through the lubrication system, reliable lubrication and cooling of engine parts at the highest permissible loads and ambient temperature depends on this indicator.
For an engine or any other mechanism, it is necessary to use oils with optimal viscosity, the value of which depends on the design, operating mode and degree of wear, ambient temperature and other factors. The viscosity of engine oil, firstly, is an indicator of its lubricating properties, since the quality of lubrication, the distribution of oil on the friction surfaces, and thus engine wear, depend on viscosity. Secondly, energy loss during engine operation depends on viscosity. The higher the viscosity, the thicker the oil film and the more reliable lubrication, but the greater the loss of power to overcome liquid friction.
Currently, the only classification system for automotive engine oils recognized in foreign countries is the specification SAE J300 (Society of Automotive Engineers USA ( Society of Automotive Engineers)).
Class Sae indicates the range of ambient temperature in which the oil will ensure that the engine cranks the starter, the oil pumping the oil through the engine lubrication system under pressure during cold start in a mode that does not allow dry friction in the friction units, and reliable lubrication in the summer during long-term operation at maximum speed and load mode.
Reference:
Degrees of Viscosity SAE
In urban traffic and in sports driving, as well as when the temperature is high, the engine is exposed to high temperatures. It is important to use oil that, at high temperature, retains its viscosity to a large extent to protect the engine.
When the engine is cold, on the contrary, the oil tends to thicken. In this case, it is important that it remains liquid even at low temperatures in order to flow through the engine, protect its parts and facilitate start-up.
Reliable engine performance is largely dependent on the viscosity of the oil, which should be selected according to the ambient temperature and operating conditions. In order to avoid improper selection of oil according to viscosity level, instead of the concepts “liquid”, “viscous”, and “high viscosity”, a special classification of motor oils by viscosity was developed.
This classification divides engine oils into 11 viscosity grades:
on the6 winter(0W, 5W, 10W, 15W, 20W, 25W) and
5 year old (20,30,40,50,60)
viscosity classes.
Oils with a viscosity class exceeding SAE 60, refer to transmission.
Summer oil it has sufficient viscosity to provide reliable lubrication at high temperature, but it is too viscous at low temperature, as a result of which at low air temperature it is difficult to start the engine.
Low viscosity winter oil facilitates cold start of the engine at low temperature, but does not provide its lubrication in the summer, when the oil temperature in the engine exceeds 100 ° C. It is for these reasons that the most widespread today are all-season varieties of oils that have a lower temperature dependence of viscosity.
Multigrade oils are denoted by a double number xxWxx, first of which indicates maximum values \u200b\u200bof dynamic viscosity of oil at low temperatures and guarantees starting properties (pumpability of oils at low temperatures), and second - defines oil viscosity at engine operating temperature (kinematic viscosity range at 100 ° C and dynamic viscosity at 150 ° C). Index W (“Winter”, that is, “winter”) means “winter”. The greater the difference between the two digits, the more uniform the oil characteristics will be when the temperature changes.
For instance, SAE 10W40,where: 10W \u003d winter viscosity 40
\u003d summer viscosity
Less number before the indexW, the lower the viscosity and the easier the engine starts in winter (i.e. the more oil will retain its fluidity in cold weather or when starting the engine). More than number after indexW, the more oil will retain its viscosity when heated. However, the viscosity of all-season oils does not change much, i.e. lubricating qualities remain high enough both in summer and in winter.
Series all season oils: SAE 0W-20, 0W-30, 0W-40, 0W-50, 0W-60, 5W-20, 5W-30, 5W-40, 5W-50, 5W-60, 10W-30, 10W-40, 10W -50, 10W-60, 15W-30, 15W-40, 15W-50, 15W-60, 20W-30, 20W-40, 20W-50, 20W-60.
Oils by SAE 10W-20, 15W-20, 20W20, 20W-30, 25W-30 are not all-weather.
Monoseasonal oils usually used when the operating temperature does not differ much (or for special tasks).
Thus, the degree of viscosity of SAE helps to determine the range of ambient temperature at which the oil will ensure the normal operation of the engine - turning it with a starter, pumping the oil through the lubrication system with a pump during cold start and reliable lubrication in the summer during long-term operation at maximum speeds and loads.
By the designation of viscosity, the nature of motor oil can be determined with almost 100% accuracy. If it is synthetic, then typical viscosity designations will be - 0W40, 5W40; if the oil is semi-synthetic - 10W40, 10W30; with the mineral nature of the oil, viscosity is usually denoted as follows: 15W40, 20W50. Although there are exceptions.
5W marked oil- the most liquid in the cold and is suitable for any cold.
Marked Oil 10Wprovides starting of the motor to -30 degrees C, i.e. suitable for daily winter driving in a moderate climate zone.
Oil with marking 15Wcan create starting difficulties at a temperature of about -25 degrees C, although with a powerful starter and a good battery, it is possible to expand the range. In a temperate climate - a suitable oil for year-round driving.
20W marked oil - for warm enough places, where extremely rarely the temperature can drop to -20 ° C. Most often, this oil is used in racing and rally cars.
The relationship between viscosity marking and the operating temperature range.
| Viscosity value according to SAE | |
| 5W - 20 5W - 30 5W - 40 5W - 50 10W - 30 10W - 40 10W - 50 15W - 40 15W - 50 20W - 40 20W - 50 | -40 …… -10
-40 …… -10 -40 …… +20 -40 …… +10/+20 -30/-20 …… +40 -30 …… +50 -30 …… +50 -22/-15 …… +50 -22 …… +50 -10 …… +50 -10 …… +50 |
In order not to make a mistake in choosing oil for the winter, it is useful to remember the so-called "Rule 35". It is necessary to subtract the winter viscosity index from the number 35 (the first digit in the designation of the viscosity of the oil), add a minus to the resulting figure - get the maximum temperature for pumping the oil. For example, 10W-40 oil (the summer index 40 does not play a role) retains fluidity up to -25 degrees Celsius (35-10 \u003d 25).
Rule 35 is ideally applicable to mineral water, but, unfortunately, is not very suitable for evaluating synthetics - it has very special viscosity-temperature characteristics. The use of synthetics or semi-synthetics as a rule changes this ratio, lowering the start temperature by another 5 degrees. So, for example, synthetics of class 10W-40 can be calculated at -50. In general, synthetics are always colder than mineral water of the same viscosity class, therefore it is almost impossible to make mistakes (and freeze) with it.
It is necessary to pay attention to the fact that, for engines of various designs, the temperature ranges for the working capacity of this class of oil according to SAE are significantly different. They depend on the power of the starter, the minimum starting crankshaft speed required to start the engine, the performance of the oil pump, the hydraulic resistance of the oil intake path and many other structural, technological and operational factors (technical condition of the car, quality of gasoline or diesel fuel, driver qualifications and other). Each automobile company, taking into account the type of engine, recommends its own range of application of the same oil, depending on the temperature of the environment. This range must be specified in the operating instructions.
The table shows the operating temperature ranges for VAZ vehicles, depending on the viscosity marking according to SAE of the common group of oils.
Interconnection of operating temperature and marking ranges
viscosity of motor oils for VAZ cars
| SAE Group | Operating temperature range, degrees C |
| 5W - 30 5W - 40 5W - 50 10W - 30 10W - 40 10W - 50 15W - 30 15W - 40 15W - 50 20W - 30 20W - 40 20W - 50 | -30 …… +20
-30 …… +35 -30 …… +45 -25 …… +30 -25…… +35 -25 …… +45 — 20 …… + 35 -2 0 …… + 45 — 2 0 …… + 45 -1 5 …… + 4 0 -1 5 …… + 45 -1 5 …… + 45 |
Of the oils developed in the former USSR and well-proven, the following motor oils should be mentioned:
It should be remembered that the SAE class of oil characterizes only the viscosity of the oil and does not provide information on its operational properties. Thus, if the designations SAE 15W40, SAE 20W50, SAE 30, SAE 5W are on the cans, this indicates only the viscosity of the oil, its fluidity, but still does not mean at all whether it is suitable for your car. The viscosity classification only evaluates the properties associated with the fluidity and viscosity of the oil, but does not provide information about all its other properties.
Preliminary recommendations for the selection of oils for viscosity:
— with mileage less than 25% from the planned engine life (or new engine) it is necessary to use class oils SAE 5W-30or 10W-30 all season;
— with a car mileage of 25-75% from the planned engine life (technically sound engine) it is advisable to apply in summeroil classes SAE 10W-40, 15W-40, a in winter — SAE 5W-30 and 10W-30, all season — SAE 5W-40;
— with a car mileage of more than 75%from the planned engine life ( old engine) should be applied in summeroil classes SAE 15W-40 and 20W-50, in winter — SAE 5W-40 and 10W-40, all season — SAE 5W-50.
When operating the engine in winter (at temperatures below -15 ° C) leading engine manufacturers recommend the use of synthetic, semi-synthetic and mineral oils with viscosity SAE 0W40, 5W40, 10W40, 0W30, 5W30, 10W30, in summer(at temperatures from -15 ° C and above) - mineral oils with viscosity SAE 15W40. For sports use
