Automobile maintenance (engine oil)

Now with the change of our living conditions, most families have their own cars. The popularity of automobile knowledge in China is very general, and the consumer market is extremely opaque. There is a simple reason. Those who know this are either repair shops, 4S shops or dealers of all auto parts or wearing parts. Most repair shops or dealers see that private car owners are like fat sheep. Basically, no one is willing to explain the advantages and disadvantages of every auto part to the owner in detail and patiently, and they will try their best to make a profit. Often the more the owner knows, the more difficult it is for him to start, which is naturally formed.

First of all, what is the main maintenance of car maintenance? Divided into the following seven categories: 1. The first step is to check and replace the oil and oil filter, mainly the maintenance of the lubrication system, which is what we often say about changing the oil. According to the quality of the oil used or the condition of the car, the oil should be maintained once every 8000- 15000 km. 2. Check whether the air filter element is related to the smooth breathing of the engine, that is to say, replace the three filters (air filter, oil filter and fuel filter); 3. Check antifreeze and glass water, which are generally added directly without quality problems; 4. Check the drive belt, generator and air conditioner compressor drive belt (all after 80,000 kilometers); 5. Check the spark plug; 6. Check the throttle valve and clean it directly if it is too dirty. The maintenance personnel have no problem, and many throttles are broken. 7. Check the brake pads and brake discs. If it is badly worn, it needs to be replaced directly. About the above things, the author has written in other articles. When to change, what brand to change is indicated. Just browsing and checking. Today, let's popularize the knowledge about engine oil.

One: What is engine oil?

At present, engine oil consists of base oil and additives. Base oil is divided into mineral base oil and synthetic base oil, and mineral base oil is produced by traditional processing or modern technology. Synthetic base oil is prepared by chemical synthesis. The additives are detergent, dispersant, emulsifier, anti-wear inhibitor, antioxidant, rust inhibitor, pour point inhibitor and viscosity index improver. The formula of engine oil is formulated after a lot of laboratory tests and engine bench tests. Adding mineral base oil is what we call mineral engine oil. If it is synthetic base oil, it is our common synthetic engine oil. There are two kinds in the market, one is all over synthetic engine oil, and the other is.

Second: the role of engine oil

1. Lubrication: The oil will form an oil film on the surface of the moving parts of the engine, which will make the relative movement between the parts smoother.

2. Cleanliness: Machine parts are constantly worn due to relative motion, especially during cold start. Circulating engine oil can take away the debris produced by wear from the surface of machine parts, thus avoiding the aggravation of wear.

3. Wear resistance: reduce friction coefficient and resistance, thus saving energy.

4. Auxiliary cooling: The engine oil circulates continuously in the oil gallery and oil pan of the engine, which actually plays a cooling role like cooling water.

5. Rust prevention and corrosion prevention: Oil forms an oil film on the surface of machine parts to isolate air and moisture from machine parts, thus achieving rust prevention effect.

6. Sealing and leakage prevention: The engine oil can form a sealing ring between the piston ring and the piston to prevent leakage and the entry of pollutants.

7. Shock absorption and buffering: Impact loads on pistons, piston fragments, connecting rods and crankshaft bearings are buffered by lubrication.

Three: brand classification of engine oil

There are many kinds of engine oils on the market, such as Mobil, Shell, Castrol, Total, Longpan, BAIC, Lion Magic Series and so on. Please note that the quality on the market is really up to standard. There are four international brands of imported engine oil: Mobil, Shell and Castrol, also known as "American Shell" and Total. Total has a good reputation and quality.

The prices of the three major brands of nail shells in the formal channels on the market are relatively transparent, and the profit margin is compressed. To a large extent, repair shops are reluctant to use Meijia shells in pursuit of profits. Many repair shops will choose to represent a brand, such as Lin Chi-ling's Longpan, Yu Rongguang's Dihang, and so on.

At this time, many car owners will ask, will it affect me to use brand-name engine oil all the year round? Tell you, if you change the brand-name engine oil that has been inspected on time, it will not have much impact. If used for a long time for several years or even longer, brand-name engine oil is more likely to produce a thick layer of grease, and the service life of engine oil is usually far less than that of "Meijia Shell" and Total. At this time, more maintenance is needed.

Tell you, in fact, most of the engine oil changed in 4S is also produced by the three companies "Meijia Shell", but before entering the 4S shop, he went through strict screening by the manufacturer and chose the one with the most suitable viscosity and performance, then changed the packaging and entered the 4S shop on the label. For example, the original engine oil of BMW is produced by Shell.

Four: How to choose all synthetic engine oil and half synthetic engine oil?

There are seven main differences between synthetic engine oil and semi-synthetic engine oil:

1, the use of base oil is different, semi-synthetic engine oil adds minerals, and all of synthetic engine oil uses synthetic base oil.

2. The replacement cycle is different. The replacement cycle in synthetic engine oil is longer than that in synthetic engine oil. In most cities in China, semi-synthetic engine oil is replaced every 7,500 kilometers or 9 months, and synthetic engine oil is replaced every 1 2,000 kilometers or1year.

3, the applicable temperature is different, and the application temperature is wider in synthetic engine oil;

4. Different automobile conditions apply. Semi-synthetic engine oil is suitable for economical cars, and all synthetic engine oil is suitable for luxury cars;

5. The TBN content of additives used is different, which is higher in synthetic engine oil and lower in synthetic engine oil.

6. synthetic engine oil is more stable;

7. synthetic engine oil protects the engine better;

To sum up, under the premise of total synthesis, total synthesis can be used as much as possible.

All synthetic engine oils must be used for the following models and conditions:

1, large displacement vehicle.

The reason is that, in addition to the heavy weight of large-displacement vehicles, the output power of the engine is very high, which will lead to the working temperature of the engine and oil being much higher than that of ordinary vehicles.

2, turbocharged models

For turbocharged engines, oil not only lubricates the engine, but also lubricates the turbine. Generally, the rated speed of a four-cylinder turbocharger is about130,000-150,000 rpm, and the turbine from high temperature to high temperature requires high durability of oil lubrication at high temperature.

3. In extreme cases

Extremely cold areas, dusty areas, severely humid areas and high temperature areas will cause great damage to the engine. Because of its high viscosity index and good fluidity at low temperature, synthetic engine oil base oil generally has a low pour point, which is beneficial to the smooth start of the engine in extremely cold environment and can reach all lubricating points quickly. At high temperature, the viscosity of engine oil changes little, which can ensure lasting oil film thickness and stable oil pressure.

4, accustomed to intense driving

Intense driving is often to increase the engine speed in order to get better driving pleasure. Driving at high speed for a long time will lead to premature engine wear.