The extended temperature range of 5W30 and 5W40 oils has made them popular with Russian car owners. Why? What benefits will the engine get from this, which oil is better: 5W30 or 5W40 in winter?
Currently there is a tendency totransition to a more extended viscosity range. The chemists have made the most significant steps in this direction with regard to the creation of synthetics, adding there all the new components. For example, Mobil, the first company to introduce synthetic lubricants to the market, has been working with it and has been experimenting for over thirty years. A huge number of competitors appeared and do not sleep and spend huge amounts of money to create a new product with advanced features. But developers who produce synthetics with a highly specialized focus, for example, for highly loaded diesel engines, there are few.
In addition to the "fives" - synthetics, there is a similarsemi-synthetics. Why not use it? Of course, you can take advantage of liquid mineral water, add thickeners, a synthetic component with a modern set of additives, and you get quite a standard semi-synthetic oil for an engine in the winter for example. However, it is known that its parameters will in any case be lower compared to synthetics. After all, the oil base plays an extremely important role, setting the physical and chemical base.
A well-known analogy can be traced with gasoline.There is a technology by which many additives are added to the low-octane A-80 gasoline in an artisanal way to produce AI-98. But, having worked on such fuel, the engine will soon require repair: at least, it will be necessary to flush the injector and replace the spark plugs. After all, it is absolutely clear that high-grade gasoline of the highest quality will be obtained only through the use of appropriate technologies.
Эта характеристика имеет для смазочной жидкости paramount importance. This parameter defines the limiting temperature for the use of oil. Therefore, which oil is better: 5W30 or 5W40 (in winter or summer) is determined precisely by this parameter. If the index is low, the lubricant should not be too viscous to cold start the motor with a starter and pump it through the pump. In the high-temperature mode, on the other hand, the oil should not have too low viscosity so that it is possible to ensure a constant required level of pressure in the system and the formation of a friction-protecting film around the parts.
So, the viscosity of the oil is divided into:
Winter. With a low viscosity, the engine will start easily, but lubrication will not work effectively at high temperatures.
Summer. Cold start will be problematic at temperatures below zero degrees, but with a high viscosity the motor will be reliably and stably lubricated in warm and hot weather.
All season. When it is cold outside, the oil shows the quality of winter lubrication, and when it is hot - summer.
Всесезонки приобретают все большее distribution, displacing the first two species, as now the need to change the oil every time when the season changes is gone. At the same time, they show themselves to be more efficient and energy efficient. An example of such a lubricant is oil 5W40 (synthetic).
Of course, other characteristics are important for the oil:detergents, anti-wear, anti-corrosion and anti-oxidation (for this are additives). However, viscosity is one of the main values. Many modern supplements increase the price. Therefore, you should always pay attention to this parameter and choose the optimal ratio of lubricant properties and future operating conditions of the engine.
The main prescription that followsguided when choosing, are the requirements of the vehicle manufacturer. They are given in the instruction manual. Usually, they not only contain information on specific properties that should be inherent in the lubricant used, but also suggest specific brands of oils with recommendations to use them. Often in the manual there is Shell oil (5W40, 5W30 or other type). At the same time, if your car is already far from new, and you have little information about its operation, you can easily choose the brand for the engine or transmission.
What do these mysterious letters SAE mean?From English, the abbreviation is translated as “Society of Automotive Engineers” (Society of Automobile Engineers). This is an international standard to which viscosity should conform. For example, in 1999, the requirements of the standard were as follows.
The kinematic viscosity of the oil determines the compliance with a particular season. It is calculated at low speeds from twenty to one hundred degrees and separately at one hundred degrees.
Starting properties are revealed throughresistance when starting a cold motor and the possibility of obtaining revolutions. Depending on viscosity and class, they are determined at a temperature of ten to thirty-five degrees of frost and high shear rates (105s-1), that is, conditions for operating in crankshaft bearings during cold start are considered.
Pumpability determines the rate of passagelubricants to friction parts during cold start, as well as the possible risk of engine breakage during cold start due to rotation of the liners. The indicator is considered at negative temperatures from fifteen to forty degrees and at low shear rates (10s-1). Under these conditions, the lubricant spreads in the pan to the oil receiver when starting the cold engine.
Viscosity at high temperature revealsa real indicator in the operation during the warm season of the highly loaded motors. Thus, the anti-wear characteristics, losses due to friction and the impact on the efficiency of the motor are visible. It is fixed at high shear rates (106s-1). Under these conditions, crankshaft bearings operate at high temperatures and loads.
This is the SAE specification that definesoil characteristics in various conditions. Currently there are six winter classes and five summer classes. Winter is easily identified by the presence of the letter W ("winter", which translated from English means "winter"). The higher the viscosity, the greater will be the numerical index.
Winter viscosity is designated 0W, 5W, 10W, 15W, 20W. 25W.
Summer - 20, 30, 40, 50.
Consider the example of oil 5W40.
Its characteristics are as follows.Class - viscosity 5W. As is clear, it can be used in winter, that is, it depends on this indicator how easy it is to start the engine in the cold. Thus, in order to understand what kind of oil to fill in in winter, you need to pay attention to this indicator.
The number "40" reveals the summer performance, that is, the possibility of the engine functioning at high temperatures.
If, as in our example, there is a designation of one and the other classes (that is, engine oil 5W40, as well as 5W30), this indicates the all-season nature of its use.
When choosing a viscosity, first of all, they are guided by the instructions of the car manufacturer. If there are none, follow the general recommendations.
Selecting the best oil for winter, you need to consider the conditions under which the vehicle will be operated.
Then problems with running in the winter and negativethe consequences for the motor (for example, rapid wear and seizure at start-up, which can occur in oil starvation conditions) can be avoided regardless of whether you are flooded with 5W30 or 5W40 for the winter. It is necessary to understand that when starting the engine, even if it does not occur during severe frost, but at a positive mark on the thermometer, time is needed for pumping the oil pump through the lubrication system so that the liquid gets into all moving parts and channels. Until that time, the engine is running under low oil conditions. Therefore, friction and wear are greatly enhanced. The more lubricant can maintain fluidity in low temperature conditions, the better protection will be provided to the motor.
Winter properties are reflected on the left side, andsummer - on the right. Thus, wondering which oil is better - 5W30 or 5W40 - in winter, you need to pay attention only to the indicator on the left, which is the same in this case.
Therefore, you should pay attention to the difference in summer mode and select the appropriate option depending on the operating conditions of the vehicle.
Starting software depends on this indicator.engine without heating, free pumping of oil through the system and, as a result, stable lubrication of all rubbing parts at the highest possible loads and ambient temperature.
Even in temperate climates, the change in wintertemperature to the biggest warming up to one hundred and ninety degrees. Therefore, seasonal oils need to be changed depending on the time of year. However, with the appearance of all-season tires (these include, for example, motor oil 5W40 and 5W30), the problem was removed. Thanks to their additives, they are able to exhibit the necessary properties at different temperatures. That is, at a negative value, they are similar to winter oils, and at high positive they are summer oils.
Additives do not greatly increase viscosity at lowtemperature, but greatly increased - at high, when the number of macropolymer molecules increases significantly. In all-season tires (which include 5W30 lubricant and 5W40 oil), the characteristics consist in a temporary possibility of changing its viscosity, also relative to the shear rate. With decreasing speed, it increases, and with increasing - decreases.
Больше всего это свойство проявляется при низкой temperature, but also at high temperatures, which has good consequences for the engine: low viscosity during a cold engine makes it easier to descend, and when it is warm, the energy loss due to friction decreases, thereby saving fuel.
Low-temperature oil characteristicopens through the pour point when the lubricant stops flowing. This indicator is realized when the temperature is five to seven degrees lower than that at which fluidity was possible.
Most often, hardening occurs due to the formation of paraffins in the cooled lubricant.
Based on the above, it is clear that in the cold season both types manifest themselves in the same way. Therefore, for the winter is perfect and one, and another type of lubricating fluid.
