The internal combustion engine is a complex mechanism where thousands of parts rub against each other at a tremendous speed. Without proper lubrication, this metal dance would have turned into a chaos of destructive friction in seconds. Exactly. motor-oil He takes on the role of protector, creating the thinnest film between moving elements.
However, the functions of the lubricant are not limited to the reduction of friction. High-quality liquid removes heat from the piston group, washes off the scoop and protects parts from corrosion. Car owners Often underestimate the importance of regular replacement, considering it a simple formality, but the power unit life depends on it.
In the modern world, the range of products on store shelves is huge and confusing. Synthetics, semisynthetics, mineral water - it is difficult to understand this without preparation. Our goal is to give a comprehensive understanding of what exactly pours into the crankcase of your engine and how not to make a mistake when choosing.
Types of oil base bases
The foundation of any lubricating liquid is the base oil, which makes up 80-90% of the canister volume. It is from its origin that the key characteristics of the product depend. Mineral oils It is obtained by direct distillation of oil. This is the cheapest option, which, however, has unstable viscosity at temperature changes and quickly oxidizes.
Synthetic products are created by chemical synthesis, which allows engineers to program their properties. Molecules synthetic They are of the same size and shape, which ensures stable operation in extreme conditions. They do not thicken in severe frost and do not evaporate at high temperatures.
The middle ground is considered semi-synthetic. It is a mixture of mineral base (usually 70-80%) and synthetic additives (20-30%). This compromise allows to reduce the cost of the product, while maintaining acceptable performance characteristics for mileage engines.
⚠️ Warning: Never mix oils with different bases without an urgent need. The chemical reaction between additives can lead to precipitation and coking of oil channels.
Classification of viscosity by SAE
The most prominent marking on the canister is the viscosity code, for example, 5W-30 or 10W-40. This classification was developed by the Society of Automotive Engineers. SAE. The first digit with the letter "W" (Winter) indicates the behavior of the oil at low temperatures, that is, at a cold start.
The smaller the number before the letter W, the thinner the oil is in the cold and the easier it is for the starter to turn the engine. The second digit characterizes the viscosity at the operating temperature of the engine (about 100 ° C). Here the rule is the opposite: the higher the number, the thicker the protective film, but also higher the friction resistance.
Incorrect selection of viscosity can lead to serious consequences. Too thick oil will not have time to reach the rubbing vapors in the first seconds of launch, causing oil starvation. Too liquid will not be able to keep the pressure in the heated engine, which will lead to wear of the liners.
For regions with harsh winters, choose oils with an index of 0W or 5W, even if the manufacturer allows 10W. This will extend the life of the starter and battery.
API and ACEA quality standards
Viscosity is not the only important parameter. The chemical composition and presence of additives are regulated by international standards. American Standard API The oils are divided into two categories: "S" (Service) for gasoline engines and "C" (Commercial) for diesel engines. The second letter of the alphabet indicates a generation: the farther it is from the beginning, the more modern the oil (SN, SP, CK-4).
European Standard ACEA It is considered more rigid and takes into account the features of operation at high speeds and long replacement intervals. It divides the oils into classes A/B (gasoline and light diesel), C (green oils for catalysts) and E (heavy diesel). For modern cars with particulate filters, compliance with the Low SAPS (low ash content) class is critically important.
When choosing a product, always focus on the tolerances specified in the instructions for your car. Using oil of a higher class than required is usually acceptable, but the reverse can be fatal to the engine.
What does the Low SAPS label mean?
These are oils with low content of sulfate ash, phosphorus and sulfur. They are required for cars equipped with particulate filters (DPFs) and catalytic converters. Conventional oil will quickly “clog” the filter with ash, which will lead to expensive repairs of the exhaust system.
Replacement intervals and factors of ageing
Car manufacturers often specify replacement intervals of 15,000 or even 30,000 kilometers. However, these figures are relevant for ideal operating conditions, which in reality are rare. Motor oil ages not only from mileage, but also from the engine's working hours.
Staying in traffic jams, short trips in winter, working in a taxi mode - all this refers to difficult conditions. In such modes, the oil oxidizes faster, loses its detergent properties and ceases to protect parts. The real resource of high-quality synthetics in the city rarely exceeds 8-10 thousand kilometers.
The state of the liquid can be determined visually, although laboratory analysis gives a more accurate picture. If the oil has turned black and lost its transparency, but it does not have the smell of burning and has not turned into tar, this is often indicative of good detergent properties. It dissolved the charcoal and kept it suspended.
☑️ Signs of urgent need for replacement
Table of oil selection by conditions
To simplify navigation in the world of lubricants, we present a comparative table that helps to determine the type of product depending on the condition of the car and operating conditions.
| Type of car / Conditions / Conditions / Conditions | Recommended framework | Replacement interval (km) | Key requirements |
|---|---|---|---|
| New car (up to 50 thousand). km | Full synthetics | 10 000 - 12 000 | Strict Manufacturer Admission, Low SAPS |
| Used car (100+ thousand) km | Synthetics/Semi-Synthetics | 7 000 - 8 000 | Increased content of anti-wear additives |
| Severe urban conditions | Synthetics | 5 000 - 7 000 | High resistance to oxidation |
| Old engines (oil consumption) | Mineralka/Semi-synthetics | 5 000 | Increased viscosity (High Viscosity) |
Replacement process and technical nuances
Oil replacement is a procedure that can be performed on your own with a minimum set of tools. The first thing you need to do is to warm up the engine to operating temperature so that the oil becomes more fluid and lighter glass from the crankcase. The car is then mounted on a flat surface or lift.
After the drain, the workout necessarily changes. oil-filter. Its rubber sealing pad is lubricated with fresh oil, after which the filter is twisted by hand with little effort. The new volume is poured through an oil filler neck.
After starting the engine, you need to let it work at idle speeds for several minutes so that the oil fills all channels and the filter. Only after that, having silenced the engine and waiting 5-10 minutes for the liquid to drain, the level is checked with a probe. It should be between the Min and Max labels.
⚠️ Note: When twisting the drain plug, observe the tightening moment specified by the manufacturer. A tug can rip the thread in the pallet, and under-twisting will lead to leakage. Use the new pad washer.
Compliance with replacement intervals is more important than the brand of oil. Cheap oil replaced on time, better than the expensive, which "threatened" for 20 thousand km.
Myths about additives and flushing
There are many myths surrounding the engine maintenance. One of them states that washing the engine before changing the oil is mandatory. In reality, if you change the oil regularly and use a quality product, you don’t need a flush. Aggressive wash fluids can dissolve deposits, which will then clog the oil receptacle mesh.
Another common myth is that “oil slug” can be cured by switching to a more viscous oil. Sometimes this helps to temporarily raise pressure, but does not solve the problem of wearing rings or oil caps. Moreover, thick oil circulates worse in a cold engine, aggravating wear.
There are also various regenerative additives. Most of them are marketing moves. Modern oils already contain a balanced additive package, and adding something else upsets the chemical balance. It is better to spend money on a more frequent replacement of a quality product than on a “miracle supplement”.
Is it true that synthetics can not be poured into an old engine?
There is a myth that synthetics “corrodes” old seals. In fact, she's just better at washing off the scoop. If the engine had deposits that played the role of seals, they can be washed out. But it's not the oil's fault, it's the consequence of the previous departure.
Can I mix different brands of oil?
It is technically possible to mix oils if they meet the same specifications (API, ACEA) and have similar viscosity. The basics of most oils are compatible. However, you should not do this in a system. When mixing different additive packages, their effectiveness may decrease. Adding "what was in the store" is permissible in an emergency, but at the first opportunity, it is better to replace the mixture completely.
How often should I check the oil level?
The optimal frequency of check is every 1000-1500 km of run or before each long trip. The engine must be cold (or warmed up, but with an exposure of 10 minutes after stopping), and the car should stand on a flat surface. A sharp drop in the level can signal a malfunction.
Does the color of the oil affect its properties?
The color of the oil is not a direct indicator of its quality or the need for replacement. Fresh oil can be amber, light brown or even greenish depending on the dyes and additives. In the process of work, it inevitably darkens due to the accumulation of combustion and oxidation products. Black oil is often a sign of good detergent ability, not necessarily a sign of dead oil.