A lot of questions about engine oils come to my site. And the most common question is - what is the difference synthetic oil from semi-synthetic oil? The question, as I consider it interesting, today I will try to answer it ...
Many choose only the best for their cars. Of course, using a synthetic motor oil is preferable to using a semi-synthetic one. But what is the difference in these oils?
- or simply "synthetics", the most advanced type of motor oil. Created using complex chemical reactions, as well as chemical synthesis. It has an improved molecular formula, due to which it practically does not oxidize, does not react (for example, with engine oil seals), has improved viscosity, and also practically does not oxidize. Synthetic oils are indeed the most advanced of the three types of oils (mineral, semi-synthetic and synthetic). Also a big plus, is that in "synthetics", there are already many additives that help increase engine compression, as well as reduce fuel consumption. Winter engine start is much easier, as low temperatures the oil doesn't thicken as much.
The only disadvantage of synthetics is the high price. It is not always meaningful to pour expensive synthetics into budget car Let's say AvtoVAZ.
– semi-synthetic engine oil in its structure it has both "synthetics" and mineral motor oil. That is, it is a kind of mixture of motor oils. It should be noted that there is no strict regulation that controls the mixture of oils. At different manufacturers different percentage of oil addition. However, it ranges from 40 to 50% synthetics. That is, in semi-synthetic oil 40 - 50% synthetics and 50 - 60% mineral oil. Thus, semi-synthetic motor oil has worst performance viscosity, percent oxidation, as well as more low level additives. Winter starting the engine is not as easy as, say, on synthetics, all because the viscosity level is much higher than that of synthetics. However, semi-synthetic options are almost half the price of synthetic ones. Therefore, its use in cheap cars is advisable.
I hope it became clear about the main differences between these oils.
Synthetics - more expensive, made by synthesis and chemical reactions, the most perfect oil.
Semi-synthetics - two times cheaper than "synthetics", but not so perfect in its composition, often diluted with cheap (compared to synthetics and semi-synthetics) mineral oil.
If you have new car It's definitely synthetic. That's all, read our AUTOBLOG.
Today, among car owners, there is a lot of controversy about which oil is better to fill in the engine. Some prefer mineral liquids, others recommend taking it, and still others do not choose anything other than semi-synthetics. In addition, they create many companies that advertise their products as the most modern and optimal. In this article, we will consider several selection criteria lubricants and find out which oil is better to fill in the engine.
Viscosity
The first thing to pay attention to is the viscosity of the lubricant. Often, the characteristics of motor oils are divided into two types - summer (that is, those that should be filled in in the summer) and winter (well, everything is clear here). So, every manufacturer, be it Opel or domestic gas, initially indicate in the operating manual the exact one that needs to be filled in at one time or another of the year. There are no exact indicators here, since each company sets its own optimal data range, and the difference between them is very large.
Car mileage
The answer to the question of which oil is better to fill in the engine directly depends on the life of the machine, that is, its total mileage. Many masters recommend that motorists use synthetic oil only for new cars. Well, for the old there is nothing better than mineral liquids. Also worth noting an exception - if you are the host sports car, which is 5 or more years old, it is better to give preference to "synthetics", since the engine in such machines runs at very high speeds.
What was the liquid before?
An examination of motor oils showed that in many ways the choice desired liquid(in particular, on used cars) depends on what lubricant their engine was previously running on. For example, if over the past 50-80 thousand kilometers the engine has been running on "mineral water", then this time it is best to fill it with "synthetics". Why? The thing is that the first type of oil, in terms of its properties, forms various cracks and deposits in the units, which can only be washed out by the second type of lubricant (it has stronger acid indicators, so it is very useful for the engine). But it is possible that “synthetics” will also wash out useful deposits, so it should not be poured a second time. But then what kind of oil is better to fill in the engine after synthetic fluid? In this case, it is best not to immediately switch back to mineral water, but to use a compromise - a semi-synthetic lubricant. Thanks to its special properties, it will not harm the operation of the engine and at the same time prepare it for the next consumption of mineral water.
As you can see, there is no definite answer to the question of which oil is better to fill in the engine. Each car is special, and you only need to fill it with the liquid that will not inhibit the operation of the engine (we just listed these cases). Therefore, take care of your iron friend and pour only high-quality liquids into it!
With the advent of various types of oils, disputes do not stop about which oil is better to choose in the engine of your car. Each type of oil has many supporters, but often their arguments are based on myths, so choosing the type of oil in a car engine needs to be approached a little more thoroughly. Mineral or synthetic oil? Or maybe semi-synthetic? This article will show the differences between the types of motor oils, what is their difference and whether it is possible to mix lubricants of different composition.
Engine oil in the engine - purpose
The original purpose of motor oils is to remove heat from rubbing parts inside the engine, as well as, if possible, to remove metal particles that form during friction. By and large, nothing has changed for a long time, and on this moment these tasks are presented when choosing an oil. However, it is worth considering the fact that with the advent of semi-synthetic and synthetic oils on the market, motorists begin to actively argue about at what temperature regime ambient air they can be used. A large number of lubricant manufacturers and their properly aligned marketing companies to attract new customers only exacerbate the matter.
Mineral engine oil
For the production of mineral oil, agricultural crops are used or it is obtained during the processing of fuel oil and the subsequent purification of processed products. Since this technology is quite simple and for many years people have successfully tried to simplify this process, then this is due to low cost mineral lubricating oils. As positive effect from the use of mineral oil in a car engine can be distinguished high efficiency in use, hydrolytic stability and slight mechanical impact when interacting with moving parts of the engine. Besides, mineral oil can interfere with other identical and natural oils have an excellent coefficient of anti-corrosion formation.
But all these positive properties mineral oils are often achieved at a comfortable temperature range 10 to 25 degrees Celsius. For the use of mineral oils at low or high temperatures ah, it is necessary to use various additives. But this is the obvious disadvantage of using mineral motor oils: at high temperatures, additives burn out, and at low temperatures, the use of mineral oils is difficult due to their high viscosity coefficient.
Semi-synthetic engine oil
Such an intermediate type of engine oil can be obtained by diluting mineral oil with synthetic oil. Experts recommend using proportions of 50% to 50% or 70% mineral to 30% synthetic motor oil.
Synthetic engine oil
The coolant for the engine is obtained by the synthesis of molecules. So during operation, synthetic oils show more qualitative indicators stability and are not so strongly affected by exposure to low temperatures. The choice of synthetic oil is desirable to be carried out according to individual parameters: the region of residence and the presence of high or low temperatures during the use of the car, the nature of driving and starting, etc. Of course, it is worth considering the fact that such oil cannot be found in nature unchanged, but it has become so firmly established in everyday life. modern life that people do not think about its origin. The price of synthetic oil is the most expensive of all the above materials, but in the presence of very low temperatures environment it is a necessity rather than a privilege.
The advantages of using synthetic petroleum products include:
- Increased anti-friction properties.
- There is practically no need to use additives, since the main part was added by the manufacturer at the production stage.
- Lower evaporation coefficient before mineral oil products.
- Use at low temperatures.
Advantages of various lubricant formulations over others
Synthetics and mineral composition - which oil is better: these oil products differ at the molecular level. The molecular structure of synthetics was achieved through long-term testing to achieve the required properties, and the molecular structure of mineral oil products was laid down by nature. If in some component synthetic oils are worse than mineral lubricants, then this is also over continuous work. But the fact is that mineral mixtures clean the engine continuously and with approximately the same efficiency, while synthetics, in turn, due to their viscosity, clean quickly enough. Because of this effect, oil filters and oil lines are literally clogged with particle deposits from the engine. In this case, with improper control of the elements oil system effect may appear oil starvation and subsequent engine failure.
Therefore, we can distinguish the main differences between the two main types of oils:
- different molecular structure.
- The different nature of the response of oils to changes in temperature, in this synthetics are much better than mineral ones.
- Different fluidity of oils: due to exposure to low temperatures, mineral oil becomes thicker, synthetics are much more versatile in use.
- Stability consists in the burnout of additives of mineral oil products, which leads to a change in the operation of the engine or its failure.
Mineral or synthetic oil? The answer will depend only on the car owner of a personal car.
Which oil is better: synthetic or semi-synthetic? What do the terms resistance and stability mean when using synthetics? This means that exposure to low or high temperatures practically does not reduce the viscosity, and hence the effectiveness of the oil for a long time. When choosing in favor of semi-synthetic oil, you should pay attention to the fact that in some cases its use is more reasonable than synthetics. For example, with a large impressive engine mileage, synthetics can give high carbon monoxide, as well as when using a car with comfortable temperatures V winter time year - up to -20 degrees Celsius. However, the replacement this oil needs to be produced more often than synthetic.
In addition to the molecular structure, oil products for engine cooling are usually divided into seasonal use: summer, winter and multigrade oil. Summer oil, due to its viscosity, is reasonable to use up to 0 degrees Celsius. Otherwise, there is a high probability that the engine will not be able to start or will fail. Marking of summer oils: SAE 20, SAE 30 and so on up to 60. The designation of the numbers indicates the viscosity of the oil at operating temperature engine, the higher the number, the thicker the oil when heated.
Winter oils are marked from 0 to 25 units with the prefix W - winter (winter). Discreteness through 5 units. The minimum threshold for the temperature regime used is determined by subtracting 40 units from a given number. For example, for oil products marked 5 W, the minimum temperature at which the correct pumping of the oil system is ensured will be -35 degrees Celsius. But for winter oil products, it is also necessary to know such a selection criterion as crankability. To determine this parameter, 35 must be subtracted from the given number, while it is safe to say that for 10 W oil, the lower limit for the safe start of a car engine is 25 degrees Celsius.
All season oils. Lubricant marking is indicated by a combination of alphabetic and digital notation winter and summer oil. As an example, 5W - 30 can be deciphered as follows: winter marking 5W and summer marking 30 says that safe launch engine can be produced at a minimum ambient temperature of -35 degrees Celsius and the maximum allowable viscosity with a working engine will be 30 units. What is the difference between 5W-30 and 5W-40? The whole difference lies in the fact that the first of the presented types of lubricants in summer period more than a season liquid consistency. Therefore, if in the region of residence most of the year is positive temperatures, then for the proper operation of the motor, it is necessary to purchase a lubricant with a higher viscosity. In winter, these oils will ensure uninterrupted engine start at -35 degrees Celsius. Viscosity table of motor oil classification:
small and useful advice on the choice of oil for a car from experts:
- Before purchasing a lubricant for your car engine, you should carefully read the recommendations for using a particular type of oil directly from the manufacturer.
- Storage of lubricants is allowed with a tightly closed container lid, which prevents air, moisture or other foreign objects from entering the used oil.
- The operation of more expensive oils is not always smart choice, this can lead to a violation of the stability of the entire oil system.
- Do not succumb to the tricks of sellers, and buy oil only hoping for their advice. It is necessary to understand that all lubricants, including mineral or synthetic oil, are produced using approximately the same technology. The whole difference lies in the quantity and quality of additives added.
- An oil change must be carried out within the time specified by the manufacturer in terms of time or vehicle mileage. However, one should take into account the fact that worn engine oil should be changed a little earlier. This is due to the need to remove more friction products and much more severe operating conditions.
- Always change oil when changing oil filter, this operation costs little money, but helps to ensure high-quality filtration of the lubricant.
- Can you mix 2 different types lubricants directly in the engine? The unequivocal answer is no! This leads to the formation of an insoluble precipitate.
- Carefully monitor the condition of the oil level in the engine, do not allow it to go beyond the upper or lower limits, which are marked on a special dipstick.
- If synthetics are flooded in the engine (for example, 10W - 40 of a certain brand), then the best option in case of necessary addition, carry with you a small container of the same oil. However, it is allowed to add a lubricant from another manufacturer, but with the same marking.
- Occasionally clean the oil system of a car engine using special means And a large number of oils. This allows you to completely renew the lubricant in the engine and completely remove metal wear products.
- Before purchasing a lubricant for an engine, you need to study its expiration date on individual packaging. Tip: to prevent the purchase of low-quality fake oil it is wiser to buy it from official suppliers or trusted sellers in sealed metal packaging. This does not exclude the possibility of forgery, but reduces it to a minimum.
Conclusion.
Now many inexperienced motorists will be able to replenish their knowledge base on whether it is possible to mix and what is the difference between various types oils. Which oil is better to fill in your car can be determined based on your knowledge of the properties and markings of these lubricants, as well as the nature of behavior at different times of the year, and not on the advice of annoying sellers and television advertising. And also determine the type of lubricant for vehicles with high mileage, because it is far from always reasonable to use expensive oil instead of a cheaper one, but effective in a particular case.
Almost all modern car owners know to one degree or another that synthetic oils are of better quality and more practical for modern engines internal combustion. However, few people really know how exactly these oils differ, and why new engines require exactly expensive synthetics, and not mineral oil with a similar viscosity.
In theory, the motor is able to run on any type of oil, the only requirement is to maintain viscosity under temperature conditions. However, the use of mineral oil on modern cars can lead to a reduction in the resource of the power unit.
What is mineral oil?
Mineral oil is an outdated technology for processing crude oil into oil, with the oil subject to only minimal processing, or simple refining. Naturally, various additives are also added to mineral oils, but this does not save the situation.
With this method of production, mineral oil retains a lot of excess impurities in its composition, which can later precipitate and pollute the engine. Some oil constituents or contaminants left over from primitive processing may subsequently emulsify. Which will also lead to a reduction in the life of the motor.
Previously, when motors had simple design, and large tolerances, mineral oil, in fact, could not affect the duration of the motor, since the motor itself was made more roughly, and minor impurities did not particularly affect it. At the same time, the technology for the production of synthetic oil on an industrial scale was not previously sufficiently developed.
Formerly engineers and manufacturers power units it was necessary to consider the use of exclusively mineral oil, which is essentially refined oil, with a modified viscosity due to simple additives.
What is synthetic oil?
Synthetic oil is already a more advanced product in terms of production process and technological solutions. So, in the process of manufacturing “synthetics”, oil is distilled to decomposition into basic pure molecules, which are subsequently assembled into the required pure product without any impurities, and by adding many necessary additives, the manufacturer receives oil with the required characteristics.
Thus, synthetic motor oil is the cleanest today, leaving behind a clean motor, and also has specific requirements for a specific motor model.
In addition to the fact that the manufacturer, by adding additives, is able to regulate the temperature viscosity in wide aisles, it is also possible to add other components that will increase the lubricity of the substance, contribute to the formation of an oil film on the motor elements, its stability, and also temperature resistance.
Is it advisable to use synthetic or mineral oil?
As mentioned earlier, motor manufacturers are constantly adjusting their units for certain possibilities. modern oil and its lubricity. So the use modern roads synthetics on the Zhiguli engine of the 80th year are thrown into the wind cash. The fact is that none of the benefits of synthetic oil on this motor will not affect its operation, and the cost of maintenance with expensive oil will increase by several orders of magnitude.
However, ordinary mineral oil is also outdated, and its use is not entirely advisable in terms of economy and service life. In this case, you can opt for a semi-synthetic oil that has low cost, and more high rates than ordinary mineral oil, thanks to modern additives, and a slightly different production process.
However, if you own a car with a modern powertrain, especially one equipped with a turbocharger, only high-quality synthetic oils will have to be used to increase the life of the engine. Moreover, each automaker, in service book, writes a specific manufacturer, the name of the oil, as well as its viscosity. Assuming use original product of this particular manufacturer.
The fact is that "synthetics" various manufacturers and series is distinguished by a set of additional additives, for which the automaker could make calculations during the production of the motor.
Benefits of synthetic oil
Clean engine
As mentioned above, when operating a car, one of the main loads falls on the power unit. At the same time, during operation, a precipitate or an admixture of fuel combustion products may form in the engine oil. Synthetic oil effectively prevents the formation of sludge, as well as impurities of combustion products.
Unlike synthetic oil, a mineral product tends to actively absorb various impurities, and subsequently form various deposits and “sludge” on the walls of the motor, which will ultimately lead to a significant decrease in its efficiency.
wear resistance
When using new oil, the mineral and synthetic versions are able to protect engine parts from wear at almost the same level. However, mineral oil loses its properties much faster, which leads to accelerated wear mechanisms. Also, synthetic product has a more stable oil film, which significantly increases the protection of metal and steel parts from any wear during the friction process.
Viscosity and fluidity
Due to the wider ability to regulate the necessary properties of synthetic oil, manufacturers are able to maintain lubricant fluidity even at low temperatures, which significantly improves engine starting in winter conditions, and also reduces the wear of the motor when working on the "cold".
Conclusion
Technologies do not stand still, and not only marketers work, but also chemists and engineers. Therefore, new technologies do work more efficiently, but everything has its place. It is necessary to use synthetic oil on those motors for which the use of “synthetics” is really vital. In simpler units, or older motors, it is quite possible to satisfy all needs with a good semi-synthetic oil, the cost of which is several orders of magnitude lower than "synthetics".
We also note that today, the car owner should only worry about the distance traveled after changing the car oil. Since the very replacement and purchase of a particular oil can be entrusted to the masters. For example, you should contact a specialized car service for changing the oil in the engine - and the specialists will independently select original oil, and will carry out a free replacement of it in the motor.
For most car owners, the word "synthetics" is akin to an unconditional guarantee of the quality of lubricants. It is believed that synthetic oil (regardless of purpose) by definition cannot be bad.
The motor becomes more powerful with it, the gearbox works clearly, the gearboxes do not hum and do not wear out. For these "wonderful" properties, motorists forgive two main shortcomings:
- high cost (artificial production technology is significantly higher than mining);
- the probability of buying a fake is higher than that of inexpensive mineral counterparts.
Let's see if a synthetic base is really a universal recipe for creating a quality lubricant.
What is synthetic motor oil?
The composition of any lubricant begins with a base. It is she who determines basic characteristics, and the ability to stabilize the work of additives (without them it is impossible to create a quality product).
Initially, all lubricants were made from natural raw materials:
- organic, that is, of plant origin (for example, birch tar or rapeseed oil);
- mineral origin, made on the basis of oil.
The first type is not interesting to us, on an organic basis automotive oils not released for a long time. Consider petroleum products. The natural mineral base has all the necessary properties, with the addition of appropriate additives, you can create a really good oil.
Actually, there was a time when there were no other options: all lubricants were made from oil. However, with an increase in the power of power units, and an increase in the number of revolutions of the crankshaft, it turned out that the mineral base in difficult conditions unstable.
It took oil with programmed properties. It became possible to make it only after the introduction synthetic base. The base fluid was recreated after the natural one, only the process was controlled by scientists from start to finish. What nature has been creating for thousands of years can be reproduced in a laboratory in a few hours.
What is synthetic oil - video
Synthetic oil manufacturing technology is quite expensive, so manufacturers have developed several production methods that differ in cost and quality.
Esters and polyglycols
This is the top league of synthetics. Oil made from these chemical compounds, does not lose its characteristics in the most severe operating conditions. It is for this reason that the ester base is used in lubricants for racing cars.
A characteristic feature is that the molecules of ester compounds have polarity, due to which the surface tension forces increase many times over. The oil seems to stick to the metal surface, providing a reliable film at the point of contact. 
It is almost impossible to tear or wash off the enveloping layer. Moreover, no temperature influences change the basic properties.
The ester or polyglycol base is 100% synthesized, so when developing a formula, you can immediately lay down the properties of synthetic motor oils, usually provided by additives. So the concept of "stratification" for such a basis is absent in principle.
Ester-based oils are sold in ordinary stores, are very expensive, and belong to the API quality standard - GL-5.
Polyalphaolefins (PAO)
The technology for the production of the base base uses by-products generated during oil production: natural gas. That is, the basis is still natural, but it is obtained as a result of 100% synthesis.
The main advantage is the ideal homogeneity of the molecular composition, while maintaining the possibility of programming the basic properties. True, additives are still added to such a base, otherwise it would be necessary to synthesize various groups of the base composition - this will make the product more expensive.
And so, the cost of PAO-synthetics is several times less than ester grease. Not to mention polyglycols - such compounds are generally not available for retail sale, they are used only for special equipment and in a racing environment.
Therefore, if you buy an oil with a 100% synthetic formula, it will be a PAO base. Such oils are classified as GL-4 (according to API classification).
Hydrotreating and hydrocracking
Engine oil for an engine should not only have outstanding properties, it should be available to the average buyer (of which the majority). If the owner of a domestic 30-year-old car decided to get away from mineral water, the price of a canister of oil should not exceed residual value car.
As a result, a formula for hydrotreating (or hydrocracking - “HC”) was developed. In principle, this is synthetic, and the inscription "synthetic" is not a marketing ploy. 
The issue is production technology. Hydrocracking is not the reproduction of new molecules, but the separation of unnecessary ones. All the same oil products are taken as the basis, “extra” components are separated from them, and long molecular chains are physically destroyed.
The result is a base that is very close in properties to 100% synthetics, but does not have the same stability. What does this mean?
You probably noticed two interesting statements in the service book of your car regarding the replacement of engine (transmission) oil:
- Change interval 10,000 km or 6 months, whichever comes first. Of course, the figures are conditional, for example.
- When operating the car in difficult conditions, the oil change interval is reduced. "Severe conditions" means any operation, except for uniform mileage on ideal roads no traffic jams or traffic lights.
These conditions apply to any oils other than ester synthetics. That is, 99% of motorists must replace ahead of time specified in the service book. When operating a car in city traffic jams, overheating occurs.
Hydrocracking synthetics lose their properties (not as quickly as mineral water, but still loses). Off-road, engine parts interact with each other under load, and the working film is not as strong as 100% synthetics.
You buy synthetic oil to get away from the problems of "mineral water" and get a surrogate.
Differences between mineral, semi-synthetic, and synthetic oils
Buying synthetic motor oils, you really get a quality that is inaccessible mineral basis, and even semi-synthetics. Even hydrocracking technology changes the properties of the base base so much that the stability of lubricants improves by an order of magnitude. 
The graph shows that after the end of the replacement period, the cracking base retains its properties much longer than mineral water and semi-synthetics. And pure synthetics allow you to increase the mileage (or service life) of the oil, in comparison with the recommendations of the car manufacturer.
Advantages and disadvantages of synthetics
High-quality oil, especially 100% synthetic, gives the motor the ability to work in gentle conditions. This extends the resource, saves fuel, increases power.
Additives, without which the operation of lubricants is impossible, remain operational almost until the end of the life of the synthetic oil. Such a lubricant can be used in harsh conditions, regardless of the climate. In the cold, synthetics do not thicken. 
However, there are also disadvantages. First of all - the price. 100% synthetics are not affordable for owners cheap cars, it remains to be content with hydrocracking. In addition, popular oils are often faked if you buy consumables at unverified outlets - there is a risk of running into counterfeit goods.
Outcome:
To decide which synthetic oil is best, analyze the operating conditions of the car. If you do not storm off-road, and do not participate in street racing, optimal choice- hydrocracking synthetics from a trusted auto shop.
The main road about synthetic oils - video
