You are needed some basis knowledge about motor oils, for caution. In the worst case, you can harm your car’s engine.In this section you can find answers to important questions regarding the choice of lubricants.
The main object of motor oil is lubricating and protection. Oil creates a thin film on the surface of friction parts, absorbs and retains combustion products and particles of metal shavings.
You should buy lubricants only in the official representative of the brand or in specialized stores, which work directly with the brand company. There is guarantee in this case, which saves your car’s engine from counterfeits that have occupied the market. When you choose oil, try to consider the requirements of the manufacturer of your car which oil and liquids to use. This information is included in the manual instruction. If the car is not new and the information given in the instruction manual is not enough (or they simply outdated), you have to pick up their own oil, based on the following parameters:
1. Viscosity grade SAE.
2 . Class quality ACEA (CCMC), API, ILSAC and QOST .
3 . Mineral, synthetic or semi-synthetic oil .
Mineral oils are made from petroleum by distillation and refining. There are two main types of mineral oils – naphthenic and paraffinic. They have a lot of additives and lose their lubricating properties very fast. Difference in structure of these oils is in their constituent hydrocarbons. Particularly suitable – paraffinic base oils have better characteristics of viscosity and temperature.
Another option to improve characteristics of a mineral oil – is hydrocracking, in which process of “rectification” of hydrocarbons takes place by rearrangement of atoms, that brings to getting isomers.
There is a disadvantage of this method that the isomerization goes in the opposite direction too, because of that hydrocracking oil is obtained with similar properties to the synthetic, but it senesce much faster than synthetic and loses its chemical properties.
The synthetic oil is produced by chemical synthesis of certain compounds, thus this product imparts the desired performance properties, namely, the maximum thermal and chemical stability.
“Synthetic» oil has a number of significant advantages over the “mineral water”:
1. High turnover reduces a friction, which ultimately leads to lower fuel consumption and a slight increase in engine power.
2 . The low temperature of pumping, which means that the engine will work at low temperatures overboard without any overloads.
3 . Synthetic oil has a high vaporization temperature, i.e. it is not so sensitive to overheating.
4 . Chemical stability of the oil remains practically throughout the entire lifecycle, because it is less oxidized during engine exploitation.
Compromise between these two types of motor oils – is semi-synthetic product. Partly synthetic oil is obtained by mixing quality mineral (petroleum) and synthetic base components. As result, we get cheaper oil than fully synthetic, but with better performance than mineral. Semi-synthetic oil can also be applied in all types of modern engines.
One of the main characteristics of the oil – is its viscosity. The easiness of cold start in cold weather depends from the viscosity. . This specification defines three types of motor oils: all-season, winter and summer. SAE – Society of Automotive Engineers . The SAE is international standard that regulates the viscosity of oils.
Winter oil is denoted by letter «W» and the number in front of it (from English . «Winter» – winter ): SAE 0W, 5W, 10W, 15W, 20W, 25W.
Summer oil denotes a prime number: SAE 20 , 30, 40 , 50, 60 .
Multigrade – this combination signs of winter and summer species such as, SAE 5W40, SAE 10W- 40.
“Winter” index represents the extent to which the minimum temperature recommended oil . while choosing “winter” viscosity grade should be guided by the values of the average winter temperature in the region in which your vehicle is operated.
Must remember that every time when you start the engine (not only in the cold season, but also at temperatures above zero), oil pumping takes some time to pump oil via through the oil system. This time the engine will just operate in the so-called oil «starvation” when sharply friction and weariness increase. It becomes clear how the oil can save fluidity at low temperatures, that it will be faster pumped on the system and provide protection for the engine startup.
There are four most common “organizations», which classify the quality of engine oil: API, ACEA (SSMS), ILSAC and QOST.
API сlassification of oils (American Petroleum Institute – The American Petroleum Institute) has two categories of oil : «S» (service) and “C » (commercial). For petrol engines are oil category «S», and for diesel – category «C». In the notation on the label , you will always see the value of two letters : the first is «S» or «C», the second is the letter of the alphabet is used to indicate the class of engine oil ( the farther from the beginning of the alphabet , the higher oil level ) .
Currently, API has the following acting classes for gasoline engines : SG ( 1989 ), SH ( 1993 ), SJ ( 1996 ), SL ( 2001 ), SM ( 2004 ), SN ( 2010 ) . And for diesel engines in passenger cars, vans and commercial vehicles : CF- 4 (1990 ), CG- 4 (1995 ), CH- 4 (1998 ), CI- 4 and CI- 4 + (2002 ), CJ- 4 ( 2010 ) . In brackets affixed year, which began to operate in any specification.
ACEA classification of oils (Association of European car manufacturers), which appeared in 1996, to more fully characterize the scope of motor oils and pays more attention to their operational properties. Oils marked with the letter (A – for gasoline engines, and E – for diesel) and a number (the larger it is, the better the oil). Hyphenate year is the year of approval or specification changes. These quality classes are listed below and ordered by the improvement of its characteristics:
Oils for gasoline engines in passenger cars, minivans , vans : A1 -96 , A2 -96 , A3 -96 , A4 -98 , A5 -2002.
Oil for diesel engines of passenger cars , minivans , vans : B1- 96 ; B2- 96 ; B3- 96 , B4- 98 , B5 -2002. (Class with the letter E does not consider – this oil for trucks) .
Since 2004, ACEA in a new class of oils C (C- 1, C- 2, C- 3, C- 4), suitable for use in both gasoline and diesel engines of the latest generation. Having Class C oils – low ash content (low sulfated ash, phosphorus and sulfur), and compatible with the latest exhaust gas treatment systems, which are very sensitive to ash.
ILSAC classification of oils (International Lubricants Standardization Approval Committee). «The International Committee of Standardization and Approval Lubricants ” for passenger car gasoline engines , created in 1993 associations AAMA ( American Automobile Manufacturers Association ) and JAMA ( Japan Automobile Manufacturers Association ). At its core – they are detailed requirements of a quality class API. Approach to their development is similar to the American classification, but it has fresh quality classes and more stringent requirements.
QOST – interstate standard in the CIS. Motor oils classified by the viscosity and performance characteristics. Oils are divided into classes (viscosity) and groups (by appointment and performance level).
Requirements of these motor oils specifications can be found in the owner’s manual, since the 90s. Moreover, remember, there is not too “good” oil. When oil’s quality is better and its classification is higher, it will better protect the “old” or worn engine.
API density helps to determine the weight of the product packaging : Density unit API = (141.5 / Relative density at 15.6 ° C) – 131.5 .
Viscosity index is the calculated parameter that determines the stability of the viscosity characteristics, which depends on the oil temperature. The higher viscosity index, the better oil flows at low temperatures and the oil film (higher viscosity) is more stable at the operating temperature of the engine, 95 – 100C.
Flashpoint shows the temperature at which the oil spontaneously ignites. It indirectly characterizes oil wasting at the operating temperature. The higher flash point the less oil will evaporate and burn below.
Pour point indicates the temperature at which the oil stops flowing . Typically, the temperature differs from the temperature at 5C steer .
Sulphated ash , wt% – an indicator for modern oils. Sulphated ash clogs catalysts. For category API SM oils and especially SN , this value must be less than 1.0 .
Alkaline number indicates the oil’s ability to neutralize the acidic environment, which inevitably is formed in the engine due to the presence of sulfur in the fuel and oil. If alkaline number is more, it is better . However, because of the limitations of modern oils ash alkaline number usually does not exceed 6-8 units.
Phosphorus and zinc mass fraction % – indicators of harmful substances for the catalysts. The lower the value the better it is. However,
These components are usually included in the package of additives, so a low value may degrade the protective properties of the oil. Compromise is required.