On the one hand, experts say that the more often we change the oil, the better. On the other hand, good oil is not cheap, and the procedure for changing the oil requires quite a lot of time, which is never enough. But how much is your car worth?
How often to change the oil is almost Hamlet's rhetoric...
Let's start with the fact that the era of cars that can be called eternal has sunk into deep and rapid oblivion. You can still find cars on the roads that are 30 years old or more. Do you think that the “swallows” that left the nest in the 2000s will be able to last as long? This is unlikely anymore. Today's automaker is not at all interested in cars scratching asphalt with tires for decades. Since the manufacturer must maintain its service infrastructure, our cars simply must break down, and new cars must regularly leave car dealerships.
That is why, when calculating the oil change interval, the automaker is in no way concerned about how long your car’s engine will last. The only important thing is how the engine will function during the service period. So if you still believe in fairy tales about the integrity of car manufacturers, then it's time to break your rose-colored glasses.
Timely oil changes are the key to engine health
How often should you change the oil in your car engine?
A clear answer to the question “How often should you change the oil?” no one will give it to you. There simply cannot be a universal answer, because you need to take into account the individual characteristics of the car and the driving style of its owner. You can always look at the recommended service interval in the book of the same name, but these are just recommendations that in no case can be regarded as the ultimate truth. For example, if we are talking about a sports car, then this car is unlikely to sit idle for months in the serpentine traffic jams of big cities. And if we are talking about a golf-class car, then you shouldn’t expect it to go out on the highway every day and cut through the space-time continuum at a speed of 200 km/h. And the oil change period for such different cars will also be different.
A qualified oil change will please both your car and you personally.
What affects the frequency of engine oil changes?
The main factors are the season, fuel quality and operating mode. Very often, manufacturers make recommendations regarding the frequency of oil changes, taking into account the “severe operating conditions” of the vehicle. What is it and what is it eaten with?
Oil change procedure
When timely oil changes in a car engine are especially necessary
There are a lot of factors that can be attributed to the conditions of “heavy use” of a car. However, we will voice only the main ones.
- Car downtime.
If the car is used irregularly, then you can be sure that the engine of such a car will last much less than one that “comes to life” every day. This is due to condensation that forms in the engine during idle time and, in combination with fuel and consumables, turns into acid, which confidently corrodes the insides of the engine. And if, when buying a car, you hear a heartbreaking story about how your grandfather only occasionally drove it to visit his grandmother, you should know that this is a rather dubious advantage. - Prolonged engine idling.
This most often occurs in traffic jams, causing the cooling system to become less efficient and the oil to heat up. - Regular transportation of large loads.
If your car is overloaded, this creates additional stress on the “heart muscle” of the car, and this leads to premature oxidation and thickening of the engine oil. - Frequent starting.
This again applies to the ubiquitous traffic jams, when drivers have to brake immediately after the car has started. The oil heats up the most at the moment when the car starts moving. And high temperature means an automatic decrease in properties. - Low quality of fuel used.
No special explanation is needed here, because everyone knows that low-quality fuel does not burn completely, and its residues mix with the oil, reducing its efficiency. - Express oil change.
If you, saving time, expect that a vacuum oil change will get away with it, and the car will get away with the engine, then you are deeply mistaken. In fact, during such a procedure, a lot of used oil remains in the engine, which in the future will negatively affect the overall performance of the engine.
From all of the above it follows that the car should be driven a lot, at moderate speeds, practically empty and on European quality gasoline. Naturally, this all sounds, at least, utopian. But still, the knowledge gained can be used to reduce the oil consumption of your “glutton”.
Longlife - extended oil change interval
Some manufacturers of automotive chemicals position their oils as having an extended drain interval. Motorists simply cannot help but fall for such advertising, because they want to believe that they are not only saving money, but also complimenting their engine. But few people know that an oil change using the longlife system can only be done if the following conditions are met:
- The manufacturer of a specific car model provides an extended oil change interval
- The car manufacturer has issued a certificate for a specific longlife motor oil
- the car is operated exactly in the mode provided by the manufacturer, as acceptable for “longlife”
So what is the optimal oil change interval for a car engine? Or rather, what should be used to determine it? To get started, follow the manufacturer's recommendations.
A bluish tint of the exhaust indicates the presence of oil particles in the gas.
Then decide which factors in the personal life of your car fall under the category of “severe conditions”.
Having tracked the unfavorable moments that your car has to endure, independently shorten the service interval that was determined by the car manufacturer.
You must remember to change the oil in your car engine on time!
Checking the oil level should become an automatic action, like breathing.
Based on all of the above, we change the oil and try not to fool ourselves.
The Vechmobile will work without requiring an oil change.
Clifford Simak. Ring around the Sun
Why change it?
Now - a little arithmetic. Let’s assume that the car’s instructions instruct you to change the oil at least every 15,000 km. At an average speed of 50 km/h this corresponds to 300 hours. If we take this value as a guide, then even at a lower average speed you can change the oil after the same 300 engine hours, although the mileage will be less.
Actually, there is a fourth way. Many readers argue that you should be guided by the amount burned. Roughly speaking, if you have burned a thousand liters of fuel, get ready to change the oil.But this method is only suitable for pedants who have the patience to collect fuel receipts and then add up the burned liters.
In addition, in this way it is difficult to compare, for example, a three-cylinder Matiz and a full-size American SUV with a V8 under the hood. Therefore, when choosing such an algorithm, you need to start from a certain average consumption for the car, taking into account its class, in order to keep your own “accounting”.
And one last thing. In some cases, it may serve as an impetus for an immediate oil change. For example, if there is a scary drop hanging on the engine dipstick that looks like tar, or, on the contrary, the consistency of the oil has begun to resemble water, then there is no time to think. It is clear that for monitoring you will have to climb under the hood from time to time, but... But we believe that this is not the worst habit.
Photo: depositphotos.com and “Behind the Wheel”
Motor oil protects the engine from overheating and corrosion, slows down the wear of rubbing parts and neutralizes the effects of harmful products of incomplete combustion of fuel - soot and soot. During the operation of the car, the oil loses its beneficial properties and requires periodic replacement.
How do engine oil characteristics change as it ages?
1. Loss of initial viscosity.
- An increase in viscosity occurs due to the accumulation of soot and carbon deposits in it, and as the light hydrocarbon fractions contained in fresh oil evaporate.
- If the viscosity is less than normal, then fuel or water has entered the oil.
2. Violation of the heat resistance of the oil. Old oil easily overheats, which leads to intensive formation of solid sediment (coke) and accelerates wear of engine parts, causing them to break.
3.Reduced flash point. The penetration of volatile fuel fractions into the oil leads to a decrease in the flash point.
4. Deterioration of the protective and detergent properties of the oil, which prevent wear and corrosion of engine parts. The reason may be the ingress of antifreeze into the oil from the engine cooling system, excessive amounts of additive decomposition products, and particles of dust and dirt.
5. Violation of the strength of the oil film.
6.Decreased base number (oil oxidation).
Important! Any motor oil has an alkaline Total Base Number and a set of additives. The higher the TBN, the longer the oil life.
7.Loss of fluidity. Engine oil curdles due to overheating. The reason is heavy loads on the engine, poor crankcase ventilation, insufficient airflow to the oil cooler, the oil level in the crankcase is below the minimum permissible level, and malfunctions in the cooling system.
Important! The longer the engine oil retains its characteristics, the longer the engine's service life.
How often does the engine oil need to be changed?
The well-established opinion that the engine oil needs to be changed after 10–15 thousand kilometers, but at least once a year, is partly correct. When determining the actual period of time before an oil change, it is necessary to take into account:
1. Brand and company of the manufacturer of the oil poured into the engine.
What kind of motor oil is there:
- Synthetic oils.
Advantages:
Heat resistance. Exceeding the temperature of the oil by 10⁰C during poor operation of the cooling system for half an hour causes the formation of coke and soot, polymerization, and also destroys the additives added to the oil. Synthetic oils practically do not lose viscosity when heated. At the same time, synthetics retain their detergent and dispersant, antioxidant and anti-corrosion properties until the next oil change. The disadvantage is the high cost compared to other motor oils.
- Semi-synthetic.
They are inferior to synthetic oils, since they are a mixture of high quality base oil (50 - 70%) and mineral oil (30 - 50%) with the addition of various additives. For example, if mineral oil loses fluidity in winter at a temperature of -35⁰C, then semi-synthetic oil is poured into the engine of a car operating in less severe conditions - at a temperature of no more than minus 20⁰C. Semi-synthetics are popular among car enthusiasts, since the technical characteristics, although worse than those of synthetic oils, are several times less expensive, depending on the brand.
- Synthetic oils based on PAO.
PAO is a fully synthetic oil produced by the synthesis of polyalphaolefins. Advantages: resistance to oxidation under temperature overloads and improved anti-friction properties that reduce fuel consumption have made this oil popular among race car drivers and fans of fast and aggressive driving.
- Hydrocracking oils.
If PAO synthetic oil is made from gas, then HC synthetic oil is obtained from heavy petroleum products. Oil produced using hydrocracking technology is 20–30% cheaper than PAO, and is practically not inferior in any technical characteristics, except thermal stability. PAO synthetics have twice as much resistance to temperature overloads, and the oil change interval is longer.
- Ester oils.
Made on the basis of esters. The main advantage is that during a cold engine start, dry friction of engine parts is eliminated due to the presence of a permanent oil film that can withstand a load of 22 thousand kg/cm². For comparison, the oil film of PAO synthetics can withstand an impact load of 6500 kg/cm². The lack of esters means that this is one of the most expensive types of oil.
- Polyglycolic oils.
It is 70% a mixture of PAO and esters, to which PAG polyester (polyalkylene glycol) is added. The “cleanest” oil that has excellent performance when starting the engine in winter cold. The viscosity of this oil is 180 units. It does not lose its properties for a long time and therefore it is called “oil for the lazy,” since PAG oil has the longest service life.
2. Operating conditions. The rate of oil aging depends on the nature of the trips. Severe operating conditions mean driving a car in urban conditions in a ragged rhythm, when the trip alternates with long periods of standing in traffic jams and high-speed driving in free areas. But traveling on long-distance highways at top speeds also negatively affects the life of the oil.
3. Features of your own car. Most automobile manufacturers do not advise changing the brand of oil recommended for a given vehicle. Switching to another oil can lead to unpredictable consequences. If the car owner decides to take such a step, then when choosing an oil, you need to consult with specialists.
4. Money factor. The table will help you compare motor oils by price (approximate, of course).
How to change engine oil?
The oil is changed at dealer auto centers or service stations. For those who want to do this themselves, but do not have the skill, it is recommended to watch the video.
- Vehicles under warranty are filled with oil of the brand and within the time limits specified in the service book.
- The usual oil change interval is 10 thousand km. Taking into account operating conditions, driving style, and vehicle characteristics, the replacement frequency can be reduced to 5–8 thousand km or increased to 15,000 km.
- The use of oil with an extended service life of up to 20–30 thousand km requires approval from the manufacturer.
- Along with changing the oil, the filter is also changed. If the engine is after a major overhaul, then after 3 thousand km only the oil filter is changed.
Bottom line
It is better to entrust the oil change to a professional - a mistake can cost you the breakdown of the entire engine. If it is not possible to use the service, try to choose the oil as accurately as possible and approach the replacement procedure as responsibly as possible.
If you think that the engine oil needs to be changed every 10–15 thousand km, as required by the service regulations, then you are wrong. Why? We will talk about this in detail below.
1 Why the service regulations are inaccurate and how the city influences them
Car manufacturers indicate oil change intervals in kilometers. However, the car engine works not only while driving, but also at idle. Therefore, when driving in city mode, it can work four times longer than when driving on the highway at the same mileage. Mileage measured by engine operating time is called engine hours.
For example, 15 thousand km of mileage on the highway averages about 200 hours, and in the city it can exceed 700 hours. As a result, the load on the engine oil increases enormously, because even at idle the lubricant is exposed to high temperatures. Moreover, in city traffic jams there is no crankcase ventilation, which reduces the oil life, i.e. the load on the lubricant increases even more.
But the longevity of the lubricant is affected not only by the number of operating hours. Driving style also plays a big role. For example, when driving along a highway at a speed of 100-130 km/h, the lubricant is subject to minimal stress, since the engine is well ventilated and does not operate at the peak of its power. As the speed increases, the load on the engine increases, and therefore on the lubrication system, as the pistons heat up to higher temperatures, and the volume of crankcase gases, which have a destructive effect, increases. The effect of increased speed is especially noticeable on small cars that have low-power engines and “short” transmissions.
Therefore, as you can see, a mileage of 10–15 thousand km is far from an accurate indicator of the need for an oil change. For example, in modern BMW cars, which have a meter that counts engine hours, the replacement period is 200–400 hours with moderate use of the car, and also provided that high-quality fuel is used. When the engine is running at or near maximum power, the oil change period is significantly reduced.
Another important point on which the service life of the lubricant depends is the type of oil used. Therefore, we will talk separately about the types of existing oils and their service life. It follows that the timing of replacement can be determined based on the mileage specified by the manufacturer only if the car is operated in country driving mode at a constant speed. But this happens extremely rarely. Therefore, the engine oil needs to be changed more often.
2 What you need to know about types of oil and their service life
As you know, motor oils come in several types:
- semi-synthetic;
- synthetic hydrocracking;
- synthetic polyalphaolefin;
- ester;
- polyglycol.
Pure mineral oils are practically no longer found. They were replaced by semi-synthetic compounds. However, they are no longer in great demand, as they have several serious disadvantages:
- have low additive content;
- severely clog the engine;
- their viscosity is not stable, i.e. it varies greatly with temperature, and also changes over time of operation of the lubricant.
As you might guess, the “survival” of these products is low compared to more modern formulations. Therefore, it is advisable to reduce the replacement time to 8-10 thousand kilometers, especially in urban vehicle operation, provided that a high-quality product from a well-known manufacturer is used.
Synthetic hydrocracking oils have recently become the most popular, since they have replaced semi-synthetics. In particular, standard oils produced by automobile manufacturers fall into this category. Often these compounds are classified as semi-synthetics, which has some truth. But due to the presence of a high-quality base in the composition, they have a more stable viscosity and durability.
Under normal conditions, high-quality hydrocracking oil can last 30 thousand kilometers. But in our conditions, of course, it’s not worth using the lubricant for so long. In addition, the processing of such oils leads to a decrease in the mobility of the piston rings, as well as coking of the engine and increased friction. Almost all synthetic hydrocracking oils are low-ash and are highly sensitive to fuel quality.
As for standard runs of 10-15 thousand kilometers, these compounds perform much better than their mineral and semi-synthetic counterparts. In addition, there are several other advantages:
- they retain additives better and therefore retain all their properties longer;
- have good cleaning properties;
- have fewer destruction products that have a negative impact on the engine.
One of the disadvantages is that these compounds do not have the best effect on the durability of the engine itself, which is associated with a reduced additive package.
Synthetic polyalphaolefin oils, unlike hydrocracking oils, do not form coking on the piston rings, practically do not burn out and have the purest decomposition products. Another positive quality is their good fluidity, which is maintained even in severe frosts. As for the timing of replacement, this product ages more slowly than its hydrocracking counterparts.
However, it should be understood that the durability of a lubricant depends not only on its base. The product always contains a complex package of additives that have their own service life. Plus, mechanical pollution that accumulates over time does not disappear anywhere. Therefore, you should not drive even with such oils for more than 400-500 hours, since further operation will reduce the engine life at an accelerated pace. Considering the high cost of these oils, it does not always make sense to use them instead of hydrocracking ones.
Ester oils can be called a new step in evolution. They are characterized by low boiling point and low friction coefficient. Theoretically, the operating time of these oils before replacement should be longer. But in practice, ester compounds often have a small additive package, as a result of which they require replacement even earlier than the standard period. That's why they are called sports, i.e. intended for short-term use. It makes sense to use ester products for engine flushing after using mineral and semi-synthetic oils for more than the prescribed period. This composition does an excellent job of cleaning the motor surface from all kinds of contaminants.
Polyglycol formulations are the most progressive. They have an even lower coefficient of friction, and are also capable of dissolving even the products of their own decomposition. They are better able to retain additives than other analogues. Unfortunately, at the moment you can only find polyglycol oil in wide access Kroon Oil. There is practically no data on its independent tests. But it is quite possible that this lubricant really can work longer than others.
From all of the above, we can conclude that car manufacturers indicate the interval between lubricant changes taking into account the use of standard oil, i.e. synthetic or semi-synthetic. However, different types of lubricants have different compositions and different amounts of additives. Accordingly, they have different service life. Unfortunately, it is impossible to determine the service life from the table characteristics. Therefore, when purchasing a particular brand of product, check out the results of several independent tests.
In any case, if the car is operated in urban conditions, you should not change the oil less frequently than every 8–9 thousand kilometers. As practice shows, in this case the engine remains clean, wear of parts is significantly reduced, and, consequently, the durability of the engine increases.
3 How often to change the lubricant to clean the engine
If you purchased a used car with an opaque service history or noticed through the oil filler neck that there is a lot of deposits on the surface of the engine, the engine should be flushed. Of course, there are special additives and flushing oils for this. But the highest quality and engine-friendly result can only be obtained by flushing the engine with engine oil.
The washing scheme is quite simple:
- the old lubricant is drained, after which the filter is changed and new oil is poured in;
- the car should travel about 2 thousand km with new oil;
- then the oil is changed again, after which the car must travel 4 thousand km;
- the next replacement is carried out after another 4 thousand.
Please keep in mind that the vehicle must be driven carefully throughout the entire engine flush cycle, i.e. in run-in mode. Otherwise, it will be impossible to achieve high-quality results.
If the engine was washed with a special additive or flushing oil, it is also advisable to drain the engine oil as early as possible. Moreover, you must first get rid of the remaining washing mixtures. To do this, you need to pour a small amount of engine oil into the engine so that the pressure indicator goes out. After this, you need to start the engine and let it run for 5-10 minutes. Then the lubricant is drained and clean oil is poured into the engine.
4 Why timely replacement is so important - subtleties and details
Finally, let’s look at why timely engine replacement is so important. The fact is that lubricant not only reduces friction between parts, but also performs several other important functions:
- prevents surface corrosion;
- removes soot, fuel combustion products and other contaminants from engine surfaces;
- participates in maintaining optimal engine temperature and also ensures its heat exchange.
If the lubricant is not replaced in time, all kinds of additives begin to decompose, as a result of which it loses its ability to perform the functions described above. In addition, combustion products accumulate in it, which settle on the surfaces of the engine. Over time, the oil channels begin to become clogged, as a result of which the lubricant does not reach the mechanisms in full. This, in turn, leads to rapid wear of parts.
Thus, timely oil changes cannot be neglected, otherwise even the most reliable engine may “knock” without reaching its allotted time. As we found out, it is advisable to replace them more often than required by car manufacturers.
Motors consume not only gasoline, but also oil. And I really want to save money on it. Will last year's oil be able to work for another season?
Car manufacturers recommend changing the engine oil every 15 thousand kilometers. Standard operating conditions allow you to drive on one fill for a year. But operating a machine in a metropolis differs markedly from standard conditions and involves increased loads on all technical components. Therefore, oil change times are reduced.
On the one hand, in a large city the mileage is small, only 30-40 kilometers on weekdays. But if, when the roads are clear, a car covers them in 20-30 minutes, then during rush hour the journey stretches for a total of 3-4 hours to work and back. Traffic congestion forces you to push in first gear along congested streets, repeating the start and stop cycles an infinite number of times. And all this time the engine burns fuel, spinning up to 3000 rpm and freezing again. Naturally, the temperature rises, the air conditioner takes a considerable part of the energy to operate the compressor, and the engine overheats.
It’s even worse when, in order to save money, the owner of the car is used to filling in cheap AI-92 instead of AI-95 gasoline, which is reflected in an increased number of detonations. Then the temperature regime of the engine goes beyond the established limits and another impossible task falls on the oil: cooling local overheating zones.
In general, traveling in a traffic jam refers to extreme operating conditions and not only reduces the service life of the mechanics, but also affects the service life of the oil. And in order to determine the service life of the oil, it is necessary to calculate it not in mileage, but in engine hours, as on special equipment.
It's easy to do. Typically, in passenger cars, 200-250 engine hours are generated over 15 thousand kilometers. This is about a year of operation at an average speed of 60 km/h, after which it is prescribed to go for scheduled maintenance.
But in Moscow, the average speed is much lower and fluctuates around 30-40 km/h. Cars sit longer in traffic jams, but their engines still do useful work. Therefore, an oil life of 200-250 engine hours is produced in Moscow over a period of 7000-8750 kilometers. And this is almost two times less mileage than the interval between maintenance prescribed by the manufacturers.As a result, the vast majority of cars in Moscow lack good lubrication. And this is dangerous for equipment, since modern synthetic oil is very afraid of overheating. Its additives change properties when exposed to temperature and stop working properly. The oil turns black and its viscosity drops. If you pull out the dipstick and look at the edge of the measuring scale, burnt oil will drip like water. Then it’s a direct route to the store for a new canister.
In general, it is better not to skimp on oil and replace it at least before the summer season. If a car under warranty is pushed around in traffic jams every day and covers over 8 thousand kilometers a year, then it is better to go to specialized technical stations to change the oil twice a year. In this case, you only need to fill in the oil that is recommended by the manufacturer for a specific model. It is selected based on the temperature conditions of the engine.
