The choice between synthetic and mineral oil directly affects the engine life when starting in the cold, when the thick liquid does not have time to lubricate rubbing vapors in the first seconds of operation.
If you ignore the specifications SAE and APIThe s, specified by the manufacturer, can be faced with a drop in pressure in the system, the formation of deposits on the pistons or even critical wear of the crankshaft liners.
Modern engines equipped with turbines and exhaust neutralization systems require liquids with a low content of sulfate ash, so the question “which oil is better” does not have a universal answer without reference to a specific tolerance of the manufacturer.
Basic types of motor oils and their properties
The fundamental difference lies in the basis of the product, which determines its stability at high temperatures and fluidity at negative values of the thermometer.
Mineral oils They are obtained by direct distillation of oil; they have good lubricating power, but quickly oxidize and thicken in the cold, making them unsuitable for modern engines with narrow oil channels.
Synthetic oils They are created by chemical synthesis, providing molecular homogeneity, high thermal stability and minimal evaporation, which is especially important for turbocharged aggregates.
There are also semisynthetic formulations that represent a compromise between price and quality, where the mineral base is improved by a package of synthetic additives.
- 🧪 Synthetics: maximum resource, protection against scalding, ideal for extreme temperatures.
- 🛢️ MineralkaLow price, suitable for older engines with large gaps, but requires frequent replacement.
- ⚖️ Semi-intelligent: balance of cost and characteristics, often used in budget foreign cars and domestic cars.
⚠️ Warning: Never mix oils of different types of bases (e.g. mineral and synthetic) as this can cause precipitation and oil ducts to fall.
Decoding of SAE marking and viscosity
abbreviation SAE The Society of Automotive Engineers (Society of Automotive Engineers) indicates only the viscosity-temperature characteristics of the liquid, and not its quality or origin.
Number before letter W (Winter) denotes low-temperature viscosity: the smaller the figure, the thinner the oil in the cold and easier to turn the engine in cold start.
Second digit after letter W characterizes viscosity at the operating temperature of the engine (about 100 ° C): a higher value guarantees the preservation of a strong oil film under load, but can increase the resistance to movement of parts.
Table of temperature and viscosity correspondence
SAE 0W - up to -35°C|SAE 5W - up to -30°C|SAE 10W - up to -25°C|SAE 15W - up to -20°C
For regions with harsh climates, it is critical to choose products with an index 0W or 5Wto ensure that the lubrication system is pumped until pressure is applied.
- ❄️ Low-temperature viscosity: determines the ability of oil not to freeze and quickly flow to the nodes of friction.
- 🔥 High-temperature viscosity: affects the protection of the engine during overheating and high revs.
- 📉 Viscosity index: shows how much the density of the oil changes with temperature change.
API Classification and ACEA Standards
American Petroleum Institute (AI)API) has developed a classification system that divides oils into two main categories according to engine type.
Marking beginning with a letter S (Service), designed for gasoline engines, and with the letter C Commercial: for diesel; the second letter in the code indicates the standard generation, where later letters of the alphabet signify higher requirements.
European Association of Automobile Manufacturers ACEA It imposes more stringent requirements on environmental friendliness, compatibility with catalysts and resistance to shear, which is especially true for modern European cars.
⚠️ Note: Using oils of lower grade (e.g., API SJ instead of SN) may result in accelerated wear and incompatibility with exhaust gas treatment systems.
It is important to pay attention to the presence of marks on compatibility with particulate filters (DPF) and catalytic converters, often marked by letters Low SAPS ACEA specifications.
Automakers' Admissions: A Key Criterion
The most important parameter in the selection is tolerance Approvals, which are issued by specific automakers after a series of long-term tests on engines.
The presence of a tolerance on the canister means that the oil has passed tests for compatibility with the materials of seals, protection against wear and formation of deposits for this brand of car.
For example, tolerances VW 504.00/507.00 It is mandatory for many Volkswagen models and MB 229.5 or 229.51 - for Mercedes-Benz, and ignoring these requirements may cause a refusal to warranty repairs.
The main rule: the admission of the manufacturer of the car is always more important than the brand of oil or its price.
Check the relevance of tolerances should be on the official websites of automakers or on the websites of major brands of oils, as the specifications can be updated.
| Manufacturer | Popular tolerances | Features |
|---|---|---|
| Volkswagen | VW 502.00, 504.00, 507.00 | Required for gasoline and diesel engines with DPF |
| Mercedes-Benz | MB 229.5, 229.51, 229.71 | Strict requirements for low ash content |
| BMW | BMW Longlife-01, 04 | Focused on increased replacement intervals |
| Renault | RN 0700, 0710, 0720 | Specific requirements for diesel engines with particulate filter |
Replacement intervals and factors of ageing
Oil resource is determined not only by mileage, but also by the motor clock, fuel quality and vehicle operating conditions.
Manufacturers often specify intervals of 15,000 km, but in urban traffic jams, where the engine is running and the mileage is not running, a real replacement is required every 7,000 – 8,000 km.
Signs of the need for urgent replacement are a change in color to black, the appearance of the smell of burning, a drop in the level or foaming of the liquid on the probe.
☑️ Checklist of check of condition of oil
The use of low-quality fuels with a high sulfur content accelerates the oxidation of oil and reduces the effectiveness of detergent additives.
Synthetics vs. semi-synthetics: what to choose
The choice between these two types is often dictated by the age of the engine and the owner’s financial ability, but synthetics are technically superior in every respect.
Synthetic oils have better detergent capacity and retain their properties longer, which allows for less frequent replacement, offsetting the higher cost of a liter.
Semi-intelligent can be justified in engines with high mileage, where increased carbon monoxide of expensive synthetic composition is economically impractical, and gaps in friction pairs have already been increased.
The transition from mineral oil to synthetic in old engines should be carried out carefully, since aggressive detergent components can wash out sediments and open leaks of glands.
How to distinguish a fake when buying
The market of motor oils is saturated with counterfeit, which can cause irreparable damage to the engine in just a few hundred kilometers of mileage.
Pay attention to the quality of the label printing: the original text is clear, the colors are saturated, and the barcode and hologram are free of defects.
Check the date of the bottling and the batch number, which should be stamped with a laser or clear font, rather than printed on a printer over the label.
Buy oil only in large chain stores or official representative offices of brands, avoiding dubious points in the markets and gas stations without certificates.
The presence of protective codes on the cover or label, which can be checked through SMS or the manufacturer’s website, is a must-have attribute of modern premium oils.
Can I mix different brands of oil?
Technically, blending is possible if the oils meet the same tolerances and classes of API/ACEA, as the basics are compatible. However, additive packages from different manufacturers can react chemically, reducing the effectiveness of protection. Short-term operation on the mixture is allowed (for example, when adding to the road to the nearest service), after which a complete change of the oil and filter is recommended.
Does the color of the oil affect its properties?
The color of the oil is not a direct indicator of its quality or origin. Basic oils can be transparent, yellowish or greenish, and the final color of the product is given by dyes and additives. The rapid blackening of oil in the engine often indicates good cleaning properties, as it keeps the combustion products in a suspended state, preventing them from settling on the parts.
How often should the oil filter be changed?
The oil filter must be replaced with each change in engine oil. Reuse of the filter is unacceptable, since the paper element is contaminated, and the overflow valve may lose its tightness, which will lead to the entry of crude oil into the engine lubrication system.