Questions addressed in the material:
- How are motor oils classified
- According to GOST, motor oils are classified based on their viscosity, purpose, and performance characteristics. Here's a breakdown of the main categories: **1. By Viscosity (according to GOST 17479.1-85 "Motor oils. Classification and designation"):** * **Single-grade oils:** These are designed for specific temperature ranges and have a single viscosity designation. Examples include: * **Summer oils:** For use in warmer temperatures (e.g., М-8Г2, М-12Г2). * **Winter oils:** For use in colder temperatures (e.g., М-4Зs, М-6Зs). * **All-season oils:** These are multigrade oils that offer a wider operating temperature range. They have two viscosity numbers, the first indicating their viscosity at low temperatures (like a winter oil) and the second indicating their viscosity at high temperatures (like a summer oil). Examples include: * **Automotive oils:** М-406, М-52s, М-6/12. * **Diesel engine oils:** М-4/6, М-5/10. **2. By Purpose and Performance Characteristics (according to GOST 17479.1-85):** * **Group A:** Oils for gasoline engines (e.g., М-8, М-10). * **Group B:** Oils for diesel engines (e.g., М-8В, М-10В). * **Group C:** Oils for air-cooled diesel engines (e.g., М-8Г2). * **Group D:** Oils for heavily loaded diesel engines and engines with turbocharging, requiring higher performance characteristics (e.g., М-12Д, М-14Д). * **Group E:** Oils for heavily loaded diesel engines operating under severe conditions, including those with turbocharging (e.g., М-12
- Motor oils are classified according to the SAE standard based on their viscosity.
- What is the API motor oil classification standard
- What types of motor oils are most often counterfeited
Any internal combustion engine cannot run without motor oil. Its purpose is to lubricate, prevent metal corrosion, lubricate rubbing surfaces, form a protective film on them, promote even heat distribution throughout the engine, and perform many other equally important tasks.
Motor oils differ in composition, viscosity, purpose, operating temperature range, and other characteristics. All motor oils consist of a base oil and additives – special supplements that improve performance. In our article, we will discuss the existing classification systems and types of motor oils, as well as how not to make a mistake with your choice. Inexpensive motor oil change for Citroen from an official dealer.
Main types of motor oils
Synthetic. More and more car owners are choosing synthetic oils for their excellent performance characteristics. Synthetics do not lose their properties in summer heat, and at the same time, they do not thicken much at negative temperatures outside the car. However, it is understood that synthetics retain such properties only within the temperature range specified for a particular type of oil. Synthetic oils provide excellent engine protection, prevent carbon deposits, clean the internal surfaces of the internal combustion engine, and have good stability of characteristics and performance properties. This group of oils got its name due to the manufacturing process; such oil is fully synthesized as a result of chemical reactions. The packaging usually indicates “Fully Synthetic.”.
Semi-synthetic. These oils are designated by the term “Semi-Synthetic”. They are mineral-based, enhanced with a good amount of synthetic additives, which allows for improved performance characteristics of the base oil, bringing them almost to the level of synthetics.
Minerals, labeled as "Mineral" on packaging. Undoubtedly, modern mineral oils are not bad, but due to their production method, they have weak characteristics. For example, such oils thicken in the cold, do not clean the engine well, and contain natural components that can burn in the engine, forming deposits and clogging oil passages, which impairs lubrication and cooling of the internal combustion engine. Mineral oils are obtained by distilling crude oil. When operating at high temperatures, the properties of mineral oils can be unstable.
Types of engine oils for cars according to GOST
- Summer oils. This group of motor oils should only be operated at ambient temperatures above freezing. Starting the engine at sub-zero temperatures will be difficult or impossible due to the viscosity of the thick oil. And if the engine does start, it will operate in an abnormal mode with increased wear and will eventually fail and require repair.
- Winter motor oils. The consistency of these oils is fluid, which allows them to be used at negative temperatures because the oil will practically not thicken in the cold. However, when operating the engine in summer heat, these oils become too fluid and can lead to engine failure, as they will not be able to provide sufficient lubrication – an oil film will simply not form on the friction surfaces.
- All-season oils. These oils are most popular with car enthusiasts because they allow the car to be operated in both winter and summer. Depending on the ambient temperature, the characteristics of all-season engine oil change. Such universal oils are very convenient. According to the adopted GOST 17479.1-2015 standard, engine oils are designated by a code containing letters and numbers.
The letter M signifies the type of consumable – motor oil. Next are numbers indicating kinematic viscosity. Then there is a capital letter, which assigns the oil to a particular category based on its performance characteristics. After the first digit, the letter “з” (z) may appear, indicating the use of special additives in the oil that affect viscosity and increase this indicator, «thickening» the oil.
The letter M designates a type of consumable material – motor oil. Next are numbers indicating kinematic viscosity. This is followed by a capital letter that assigns the oil to a particular category based on its performance characteristics.
Types of motor oils according to SAE classification
The SAE (Society of Automotive Engineers) community originates from the USA. This community participated in the development of the international classification of motor oils based on one of their main properties – viscosity. Viscosity, or oil flow, is the main parameter that determines the engine's operability at a given ambient temperature.
SAE defines the temperature range at which safe engine start-up and operation are possible. Viscosity is indicated in arbitrary units; the higher the number, the higher the oil's viscosity. Currently, there are 11 viscosity grades in use: 5 for summer, ranging from 20 to 60 without letter designations, and 6 for winter, ranging from 0W to 25W.
Negative temperatures:
- 0W – up to -35 degrees Celsius.
- 5W - to -30 degrees Celsius.
- 10W - down to -25 degrees Celsius.
- 15W – down to -20 degrees Celsius.
Positive temperatures:
- 30 – from +25 to +30 degrees Celsius.
- 40 – down to +40 degrees Celsius.
- -50 to +50 degrees Celsius.
- 60 – to +60 degrees Celsius.
