Some advice on selection of engine oil

When it is time to change the engine oil, the question of "do not shed or shed?" No longer occurs. And the main challenge is not that what oil brand preferred, but in how to properly select its type - regardless of who manufactured the product.

Typically, motorists do not study carefully the inscription on the label. And in order to "decode", you need to understand the basic standards for motor oils.

Viscosity - not an indication of quality.

The first thing that strikes one in studying the label oils - a class of its viscosity. And because we are spoiled by creature comforts such as multigrade oils, it would only address them.

Throughout the world adopted the classification of oils on the viscosity developed by the Society of Automotive Engineers USA (Society of Automotive Engineers - SAE). All, of course, familiar with such markings as 5W-40, 10W-40 and so on. What do they mean?

The first number with the letter W (Winter - winter) shows oil supplies to the so-called winter, low-temperature viscosity of the class. The first number indicates how easy it is to pump oil to the lubrication system, ie, how quickly will reach the working surface of parts, and how much energy the battery will be spent on the starter drive (viscosity at 40 ° C). Number, which is listed after the dash - this summer (high) class of viscosity, corresponding to oil viscosity at operating temperature of the engine (at 100 ° C).

Wrong those who think that these figures can be simply picked up and measured. Because the value of which we have just said - the so-called collective numbers. These classes are assigned to the integrated oil after measuring its performance (eg, dynamic and kinematic viscosity).

There is another important point. It is considered that, for example, oil with a viscosity of 10W-40 is better than 15W-40. This is due to the fact that many are accustomed to following patterns: a class of synthetic viscosity of 5W-40, polusintetika - 10W-40, mineral water - 15W-40. But in our market is already represented the company, which produces 100-percent synthetic viscosity grades 10W-40, 10W-60, 15W-50, 15W-60 or even 20W-60.There are mineral oils "unconventional" viscosity, for example, 10W-30. Therefore, should remember that the viscosity is not the main indicator of the quality or the basic components of oil. And to clarify, synthetic or not it is better simply to read his response.

API - not just a sign of quality.

Following standard - API, developed by the American Petroleum Institute. Some sellers are presented with buyers this classification as a peculiar mark of quality - they say, the higher the class, the better. In fact, this is only the separation of oils on performance properties.

According to the API are divided into oil and lubricants for gasoline engines (category S) and diesel (category C). Each of these categories, in turn, is divided into classes.

With oils for diesel engines it's simple. They mostly belong to CF. This means that the product is suitable for use in highly diesel engines as a turbocharged, and without it.

Classification of oils for engines running on gasoline, more diverse. Let's start with the classes SF and SG, as earlier they no longer relevant. SF oils are designed for motor vehicles running in production from 1980 to 1989., SG - for its cars and light trucks in 1989 - 93 years of manufacture. Demand for these products due to its low price and match the requirements of engine manufacturers are not manufactured anymore and outdated.As an example motors "VAZ" "classics", which is enough oil to meet the requirements of class SG.

Standard SH was designed for engines, production of which began in 1994, and supersedes all previous classes.But just a mid-90's technological advances began to move forward by leaps and bounds. Therefore, "the board" class SH did not last long.

His successor, Class SJ, adopted in 1996, largely corresponds to the SH. The only difference is the additional requirements for oil consumption, fuel economy and the ability of oil does not form deposits when heated. This class is approved by most manufacturers for use in the engines of 90 years of manufacture.

But for modern cars these requirements was not enough. Therefore, in the latest petrol engines used oil, the relevant class of SL, who entered in 2001. Unlike previous, oil class SL characterized more stable, less volatile and sufficient resources to increase the service life before replacement (if recommended by the manufacturer of the engine).

Savings can not always.

Third whale "classification avtomasel introduced ACEA (Association of European car manufacturers). On its "subtleties" know not all professional sales and service centers wizard. In vain. After all, if you do not pay attention to the classes of ACEA, the need to overhaul the engine can occur much earlier.

Among the oils is the so-called energy saving. By name easy to guess that they are designed to save fuel. Due to what it achieved? There is such a figure as the HT / HS (High temperature / High shear viscosity) - oil viscosity under high temperature and high shear rate. Conventional oil at a temperature of 150O C remains sufficiently viscous (HT / HS> 3,5 mPa • s), with no fuel economy, but provide the normal protection of the engine. If under these conditions, the viscosity decreases more (HT / HS from 2,9 to 3,5 mPa • s), details of the engine move more easily, providing a saving of fuel. So this oil is called energy saving. But it is easy to guess, while simultaneously decreasing the thickness of the oil film that will protect parts from wear at high temperatures.

Obviously a negative attitude towards energy-saving oil is not worth it. In fact some engines are designed precisely "beneath them". This is mainly motors Japanese automakers. Only these oils can easily reach the sites of friction on their narrow the oil line. Resource such engines this does not diminish. Energy-saving oils can be used only if they are recommended by the manufacturer of the car! For example, BMW and Mercedes-Benz does not recommend them. You can not use them as in most any brand of old cars, engines are in need of enhanced protection. So it turns out that the savings can not always.

Consider two categories of classification of ASEAN, which relate to passenger cars. Category A - is the oil for gasoline engines, B - for diesel. By the principle of energy conservation, they are structured the same way.Classes A1, A5, B1, B5 - Energy saving. Others (A2, A3, B2, B3, B4) - standard. And if you remember this uncomplicated principle, it would not buy energy-saving oil for an old car, the engine which needs to be reinforced protection.

Collective responsibility.

All three "pillars" of classification avtomasel linked. For example, if the API oil belongs to the class is not higher than the SH, then by ACEA it can not comply with energy-efficient grade A1 or A5, as well as the requirements for energy efficiency came only from the class of SJ. At the same time, if ASEAN has a product class A5, then the API must conform to SL, since only the classes at this level is the resource requirements for the extended mileage between oil changes. Another link - universal oils are divided into two classes: petrol and diesel, both on the API, and ASEAN.

Classes viscosity also have links with the classification of ACEA. Typically, energy-saving classes A1, B1, A5 and B5 correspond to high-performance 30 and below (eg, 5W-30, 10W-30, and so forth). And oil with an exponent of 40 and above (eg, 5W-40, 15W-50) correspond to the classes A2, A3, B2, B3, B4, that is energy-saving are not.

Viscosity (Viscosity) - The internal friction or resistance to flow of liquid. This characteristic is an important physical and chemical properties of oil, affecting the force of friction. There are two indicators: the kinematic and dynamic viscosity.

From relocation ...

The order of the categories S and C in the index is not accidental. If the label says, for example, «SJ / CF», hence, oil universal and is designed for gasoline and diesel engines, but it is preferable for use in gasoline. If on the contrary - «CF / SJ», it is a universal product, focusing more on diesels.

Practice of application.

Now, on the application. For "Zhigulenka or an old foreign cars (70 - 80 years of issue) is quite suitable oil with indicators SAE - 15W-40, API - SF / CD or SG / CD, ACEA - A2/V2. If you're furrowing the boundless expanses of the homeland with the FWD or foreign car VAZ 90, opt for oil SAE 15W-40 or 10W-40, by API - SH / CF and SJ / CF, ASEAN - A3/V3. For the latest car engine parameters oils should be as follows: SAE - 5W-40 or 0W-40, API - SL / CF, ACEA - A3/V3/B4. Note that this list does not mention energy-saving classes and standards. Their use is specific. Therefore, if you want to know exactly what kind of oil is recommended for use in your car, look in the manual. If not, before buying some effort to open the catalog on the selection of oils and find your model to continue to consciously control the process of the correct selection of lubricants.

According to the ACEA motor oils are divided into three classes: A - oils for gasoline engines; E - Oils for diesel engines of low power (Light Duty), installed in passenger cars and light trucks, and E - Oils for powerful diesel engines (Heavy Duty).