How often to change the engine oil? The procedure for changing the oil in a car engine. When to change your engine oil When to change your engine oil

Many car owners do not know how much to change the oil in the engine of their car or doubt the data provided by the manufacturer on the frequency of replacing consumables. And for good reason. through every 10-15 thousand kilometers often not quite right.

Better at it be guided by the number of hours worked and the average speed. In answering the question of how often to change the oil in the engine, there are many components. Among them are the recommendations of the automaker, the operating conditions of the car (heavy / light, in the city / on the highway, often / rarely used), mileage before oil change and total mileage, technical condition of the car and the oil used.

Also, the frequency of changing the oil in the engine is influenced by additional factors - the number of hours, engine power and volume, the time since the last oil change (even without taking into account the operation of the machine). Next, we will tell you in detail about how often to change the oil in the engine, how it happens, and other things that will surely be useful to you.

For those who do not want to go into details and understand everything in detail, we will immediately give an answer according to the shift interval: in urban conditions, the oil “works” 8-12 thousand, on the highway / light driving without traffic jams it works out up to 15 thousand km. The most accurate way to find out when to change can only be given by a laboratory analysis of oil recovery.

What affects the frequency of replacement

Each automaker in the manual for the car contains detailed information on when to change the engine oil. However, the fact is that this information is not always correct. As a rule, the documentation contains a value of 10 ... 15 thousand kilometers (in each individual case, the number may differ). But in fact, several factors affect the mileage between replacements.

10 indicators affecting the timing of engine oil changes

1. Type of fuel (gas, gasoline, diesel) and its quality
2. Engine capacity
3. Brand of previously filled oil (synthetic, Semy-Synt, mineral oil)
4. Classification and type of oils used (API and longlife system)
5. Engine oil condition
6. Replacement method
7. Total engine mileage
8. Technical condition of the car
9. Operating conditions and modes
10. Consumable quality

The manufacturer's instructions are not included in this list, since for him the service interval is a marketing concept.

Operating modes

First of all, the timing of changing the oil in the engine is affected by car operation. Without delving into the essence of the various transients, it is worth mentioning two main modes - on the highway and in the city. The fact is that when a car drives along the highway, firstly, the mileage runs much faster, and secondly, the engine cools down normally. Accordingly, the load on the engine and on the oil used in it is not so high. On the contrary, if the car is used in the city, then its mileage will be significantly lower, and the load on the engine will be higher due to the fact that it often stands at traffic lights and traffic jams with the engine running. Cooling will be insufficient.

In this regard, it would be more competent to calculate how much oil in the engine needs to be changed, based on engine hours, as it is done in cargo, agricultural and water engineering. Let's take an example. 10 thousand kilometers in urban conditions (with an average speed of 20 ... 25 km / h) the car will pass in 400 ... 500 hours. And the same 10 thousand on the highway at a speed of 100 km / h - only for 100 hours. Moreover, the operating conditions of the engine and oil on the track are much milder.

Driving in a metropolitan area rightly equates to driving on hard off-road in terms of how it destroys oil. This is especially true when its level in the crankcase is below average, and even worse when it is below the minimum level. Also remember that in hot summer weather, the oil is subjected to a much greater load due to high temperatures, including from hot road surfaces in megacities.

Engine size and type

What affects the frequency of oil changes

The more powerful the engine, the easier it is for it to survive load changes, as well as difficult operating conditions. Accordingly, the oil will not have such a strong effect. For a powerful motor, driving along the highway at a speed of 100 ... 130 km / h does not have a significant load, it will be below average. As the speed increases, the load on the engine, and hence on the oil, will change smoothly.

Another thing is a small car. As a rule, they are equipped with a “short” transmission, that is, the gears are designed for a small speed range and a range of operating speeds. Accordingly, small engines experience greater loads in critical conditions than powerful ones. When the load on the motor increases, the temperature of its pistons also increases, and the amount of crankcase gases also increases. This leads to an overall increase in temperature, including the temperature of the oil.

It is especially hard for small forced engines (for example, 1.2 TSI and others). In this case, the load is also supplemented by a turbine.

Additional factors

These include high temperature control (operating temperature), poor ventilation of the engine crankcase (especially when driving in urban conditions), the use of low-quality or unsuitable oil for this engine, the presence of dirt in the oil channels, a clogged oil filter, the operating temperature range of the oil.

It is believed that the optimal oil change interval in the engine is from 200 to 400 hours under various operating conditions, with the exception of maximum load, including driving at maximum speed and maximum speed.

Also of great importance is the type of oil used -, or completely. You can read about each of the mentioned species separately at the links provided.

Why you need regular oil changes

Dashboard display

What can happen to the car if you do not change the engine oil for a long time? To answer this question, you need to understand what functions it performs. Any oil consists of the so-called “base” and a certain amount of additives. It is they who protect the engine parts.

During the operation of the machine, and even its parking, there is a continuous chemical destruction of additives. Naturally, when driving, this process is faster. At the same time, natural deposits are formed on the engine crankcase, oxidative processes occur with individual components of the oil, its viscosity and even the pH level change. These facts are the answers to the question - why change oil at least once a year.

Some automakers and manufacturers of motor oils indicate how long it takes to change the oil in the engine not by mileage, but by frequency, usually by months.

And with a significant load, the described processes in the oil occur at an even greater speed. Especially at high temperatures. However, modern manufacturers are constantly improving the technology and chemical composition of their oils. Therefore, they are able to withstand pollution and high temperatures for a long time.

In many modern cars, the ECU constantly monitors how long it takes to change the engine oil. Naturally, this decision is made on the basis of an empirical methodology. It is based on actual data - the average number of engine revolutions, oil and engine temperatures, the number of cold starts, speed, and so on. In addition, the program takes into account errors and technical tolerances. So the computer only tells the approximate time when you need to change the engine oil.

Unfortunately, on the shelves of stores not only in the Russian Federation, but also in other CIS countries, a large number of low-quality or simply fake motor oils are currently being sold. And given that our fuel is often of poor quality, the frequency of oil changes still needs to be adjusted. In particular, if we talk about how many km to change the oil in the engine, then the recommended amount should be reduced by about a third. That is, instead of the often recommended 10 thousand, change after 7 ... 7.5 thousand.

Change the oil AT LEAST once a year, whether you operate the machine or not.

We list the causes and consequences of untimely replacement of engine oil:

• Deposit formation. The reasons for this phenomenon are the process of destruction of additives or contamination of the oil with combustion products in the crankcase. The consequences are a significant decrease in engine power, an increase in the content of toxic substances in exhaust gases, and their blackening.
• Significant engine wear. Reasons - oils lose their properties due to changes in the composition of additives.
• Increasing the viscosity of the oil. This can happen for the same reasons. In particular, due to oxidation or a violation of the polymerization of additives due to improper selection of oil. The problems arising from this include difficulties with oil circulation, significant wear of the engine and its individual elements. And the resulting oil starvation of the engine can lead to, in critical cases, even engine failure is possible.
• Rotation of connecting rod bearings. This is due to clogging of the oil channel with a thickened composition. The smaller its cross-sectional area, the greater the load on the connecting rod bearings. Because of this, they overheat and crank.
• Significant wear of the turbocharger(if available). In particular. high risk of damage to the rotor. It occurs due to the fact that the used oil has a significant impact on the compressor shaft and bearings. As a result, they are damaged and scratched. And besides this, dirty oil leads to clogging of the compressor lubrication channels, which can lead to its jamming.

Do not operate the machine with burnt and thickened oil. This exposes the motor to significant wear.

The problems described above are typical for machines operated in urban environments. After all, it is considered one of the most difficult for the engine. Next, we present interesting factual data that were obtained experimentally. They will help you decide after what mileage to change the oil in the engine.

Results of experiments with oils

Specialists of the well-known automotive magazine "Behind the Wheel" conducted a six-month study of several types of synthetic oils under the conditions of operation of cars in city traffic jams (at idle). To do this, the engines worked for 120 hours (analogous to a run of 10 thousand kilometers along the highway) at 800 rpm without cooling. As a result, interesting facts were obtained ...

The first is the viscosity of all engine oils during prolonged idling up to a certain (critical) moment significantly less than when driving “on the highway”. This is due to the fact that at idle there is a passage of exhaust gases and unburned fuel into the engine crankcase, where it all mixes with oil. In this case, some (insignificant) amount of oil may be in the fuel.

The value of the drop in viscosity of engine oil is about 0.4 ... 0.6 cSt (centistokes). This value is within 5...6% of the average level. That is, the viscosity is within the normal range. However, this only happens up to a certain point.

Clean and used engine oils

Approximately 70...100 hours(each oil is different, but the trend is the same for everyone) the viscosity begins to increase sharply. And much faster than when working in the “track” mode. The reasons for this are as follows. The oil is constantly in contact with the products of incomplete combustion (as described above), and reaches its critical saturation. The mentioned products have a certain acidity, which is transferred to the oil. Also affected by the lack of ventilation and low turbulence of the air-fuel mixture due to the fact that the piston moves relatively slowly. Because of this, the fuel combustion rate is below average, and the ingress of exhaust gases into the crankcase is maximum.

The widespread opinion that a large amount of dirt is formed in the engine during idling has not been experimentally confirmed. However, the amount of high-temperature deposits was small, and the amount of low-temperature deposits was large.

As for the wear products, their amount is much greater for the oil operated in the “plug” mode than for the one that was on the “highway”. The reason for this is the low speed of the pistons, as well as the high operating temperature of the oil (lack of ventilation). As for waste, each oil behaves differently. However, it can be argued that due to high operating temperatures and an increase in density, waste will also increase.

Based on the information provided, we will try to systematize the data and answer the question of how many kilometers to change the oil in the engine.

Next, we will dwell on the question of how often to change the oil in the engine. As mentioned above, the recommendations of car manufacturers should be treated with a great deal of skepticism. Not to completely ignore them, but amend. If you drive a car only in city conditions (according to statistics, there are a majority of such car owners), then this means that the oil is used in heavy mode. Remember that the less oil in the crankcase, the faster it ages. Therefore, its optimal level is slightly lower on the indicator probe.

How many thousand to change the oil in the engine?

Calculation of engine hours for oil change

Above, we wrote that it is more competent to calculate the frequency of oil changes based on engine hours. However, the complexity of this technique lies in the fact that it is sometimes difficult to convert kilometers into hours, and based on this information, get an answer. Let's take a closer look at two methods that allow empirically, however, it is quite accurate to calculate how much to change the synthetic (and not only) oil in the engine. To do this, your car must have an ECU that shows the average speed and fuel consumption over the last at least one thousand kilometers (the more mileage, the more accurate the calculations will be).

So, the first method (calculation by speed). To do this, you need to know the average speed of your car over the last several thousand kilometers and the car manufacturer's recommendations at what mileage you need to change the oil. For example, the mileage before an oil change is 15 thousand kilometers, and the average speed in the city is 29.5 km / h.

Accordingly, to calculate the number of hours, you need to divide the distance by the speed. In our case, this will be 15000 / 29.5 = 508 hours. That is, it turns out that in order to change the oil under these conditions, it is necessary to use a composition with a resource of 508 hours. However, in reality, such oils simply do not exist today.

We offer you a table that shows the types of engine oils and their corresponding engine hours according to API (American Petroleum Institute):

Let's assume that the car engine is filled with SM/SN class oil, which has a service life of 350 hours. To calculate the mileage, you need to multiply 350 hours by an average speed of 29.5 km / h. As a result, we get 10325 km. As you can see, this mileage is very different from the one that the automaker offers us. And if the average speed is 21.5 km / h (which is more typical for large cities, taking into account traffic jams and downtime), then with the same 350 hours we will get 7525 km of run! Now it becomes clear why it is necessary to divide the mileage recommended by the automaker by 1.5 ... 2 times.

Another calculation method is based on the amount of fuel consumed. As initial data, you need to know how much fuel your car consumes per 100 kilometers according to the passport, as well as this actual value. It can be taken from the same ECU. Suppose that according to the passport the car “takes” 8 l / 100 km, but in fact - 10.6 l / 100 km. Mileage for replacement remains the same - 15,000 km. We derive the proportion and find out how much in theory the car has to spend to overcome 15,000 km: 15,000 km * 8 liters / 100 km = 1200 liters. Now let's do the same calculations for actual data: 15000 * 10.6 / 100 = 1590 liters.

Now we need to calculate at what distance it is necessary to draw actual oil change(that is, how much the car will travel on a theoretical 1200 liters of fuel). Let's use a similar proportion: 1200 liters * 15000 km / 1590 liters = 11320 km.

We present to you an electronic calculator that will allow you to calculate the value of the actual mileage to an oil change using the following data: theoretical fuel consumption per 100 km, actual fuel consumption per 100 km, theoretical distance to oil change in kilometers:

However, the simplest and most effective method of checking is a visual inspection of the condition of the oil. To do this, do not be lazy to periodically open the hood and check if the oil has thickened or burned. Its condition can be assessed visually. If you see that the oil is dripping from the dipstick like water, then this is a sure sign that the oil needs to be changed. Another interesting method of checking is by spreading the composition on a napkin. A very thin oil will form a large and runny slick that will tell you when it's time to change the fluid. If this is the case, immediately go to a car service or carry out the procedure yourself.

How often to change the oil in a diesel engine

As for diesel engines, the same calculation logic applies here as for gasoline units. It is only necessary to take into account that the working fluid in them is subjected to greater external influences. As a result, it needs to be changed a little more often. In addition, domestic diesel fuel has a high sulfur content, which adversely affects the car engine.

Regarding the indications given by the car manufacturer (especially for Western manufacturers), they, like gasoline engines, must be divided by 1.5 ... 2 times. This applies to passenger cars as well as vans and light trucks.

As a rule, most domestic car owners of cars with diesel engines change the oil every 7 ... 10 thousand kilometers depending on the machine and the oil used.

Theoretically, oil selection is based on total base number (TBN). It measures the amount of active anti-corrosion additives in an oil and indicates the tendency of their formulations to form deposits. The higher the number, the greater the oil's ability to neutralize acidic and aggressive products formed during oxidation. For diesel engines, TBN is in the range of 11...14 units.

The second important number that characterizes the oil is the total acid number (TAN). It characterizes the presence in the oil of products that provoke an increase in corrosion and wear intensity of various friction pairs in a car engine.

However, before deciding how many hours to change the oil in a diesel engine, you need to deal with one nuance. In particular, is it possible to use engine oils with a low base number (TBN) in countries with low-quality fuel (in particular, Russian, which contains a large amount of sulfur)? During the operation of the engine, and, accordingly, the oil, the base number drops, and the acid number rises. Therefore, it is logical to assume that the intersection of their graphs at a certain vehicle mileage tells us that the oil has completely exhausted its resource, and then its operation only destroys the engine. We present to your attention the test graphs for four types of oils with different indicators of acid and base numbers. For the experiment, four types of oils were taken with the conditional names of the letters of the English alphabet:

• oil A - 5W30 (TBN 6.5);
• oil B - 5W30 (TBN 9.3);
• oil C - 10W30 (TBN 12);
• oil D - 5W30 (TBN 9.2).

As can be seen from the graph, the test results were as follows:

• oil A - 5W30 (TBN 6.5) - was completely used after 7000 km;
• oil B - 5W30 (TBN 9.3) - was completely used after 11,500 km;
• oil C - 10W30 (TBN 12) - was completely worked out after 18,000 km;
• oil D - 5W30 (TBN 9.2) - was completely used after 11,500 km.

That is, oil for heavily loaded diesel engines turned out to be the most resistant. What conclusions can be drawn from the given information:

1. A high base number (TBN) is critical for those regions where poor quality diesel fuel (in particular, with high S impurities) is sold. The use of such oil will provide you with a longer and safer operation of the engine.
2. If you are confident in the quality of the fuel you use, then it will be enough for you to use oils with a TBN value in the region of 11 ... 12.
3. Similar reasoning is valid for gasoline engines. It is better to fill in oils with TBN = 8...10. This will give you the opportunity to change the oil less often. If you use oil with TBN = 6...7, then in this case, be prepared for more frequent fluid changes.

From general considerations, it is worth adding that in diesel engines it is necessary to change the oil a little more often than in gasoline ones. And it is worth choosing it, among other things, by the value of the total acid and alkaline numbers.

conclusions

Thus, each car owner must decide for himself how much to change the oil in the engine. This must be done according to individual circumstances. We recommend that you use the calculation methods for engine hours and gasoline consumption given above (including calculators). In addition, always visually assess the condition of the oil in the engine crankcase. So you will significantly reduce the wear and tear of the engine of your car, which will save you from having to carry out expensive repairs. Also, when replacing, buy high-quality oils recommended by the manufacturer.

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 manual for the car prescribes 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 guideline, then even at a lower average speed, you can change the oil after the same 300 hours, although the mileage will be less.

Actually, there is a fourth way. Many readers argue that one should be guided by the amount burned. Roughly speaking, I 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 checks and then add up the burned liters.

In addition, it is difficult to compare, for example, a three-cylinder Matiz and a full-size American SUV with a G8 under the hood in a similar way. Therefore, when choosing such an algorithm, you need to start from a certain average consumption for a car, taking into account its class, in order to maintain your own "bookkeeping".

And the last. In some cases, it can serve as an impetus for an immediate oil change. For example, if a frightening drop that looks like tar hangs on the engine dipstick, or, on the contrary, the oil has begun to resemble water in consistency, 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 Driving

For most car owners, the question: how often and when to change the engine oil simply does not exist. After all, there is a service book, where it is clearly written: after 10 - 15 thousand kilometers, what is there to think about? But as we can see, neither the mode of operation of the car nor the quality of the filled one are taken into account here. In fact, everything is somewhat more complicated, and if you take into account only the mileage, determining when to change the oil in the engine, and not paying attention to the operating conditions of the engine and the characteristics of the engine oil, the choice of replacement frequency will not be optimal. I operate the car in especially severe winter conditions, do not forget to change the oil for summer in the spring, and change the oil for winter in the fall.

Effect of engine operating conditions on oil

Equal mileage in the city and on the highway is almost a threefold difference in the time of the engine. For example, to overcome 15 thousand km in urban mode with traffic jams and speed limits, the motor will have to work for about 600 hours, but outside the city no more than 250. This huge difference in operating time leads to the fact that in urban operation the oil loses its properties much faster if you count by mileage. After all, the temperature effect on it, even when the motor is running with a small load, is quite large. In modern powertrains, the operating temperature is quite high, which enhances this effect.

On the track, loads can also vary significantly. The car at speeds up to 130 km / h does not have to experience even medium loads. Therefore, the oil in the engine at such speeds experiences minor loads and almost does not lose its qualities. Machines with a powerful motor at such speeds experience minimal load at all. This means that their negative impact on engine oil in such conditions will be small.

At high speeds, along with an increase in the load on the power unit, the load on the oil also increases.

On cars with low-power motors and with a small transmission ratio, at speeds above 130, the oil has a very hard time. With an increase in the load on the engine, the conditions for its operation worsen - the temperature of the pistons increases, the volume and pressure of the crankcase gases, destructively acting on its base, increase.

Optimum operating conditions for engine oil

• the speed of movement, which is half the maximum allowable for this vehicle;
• short idling time after warming up;
• good crankcase ventilation;
• compliance with the temperature regime of the internal combustion engine.

If we focus on car manufacturers that give recommendations on the engine oil change interval in engine hours, then the typical oil change period is from 200 to 400 hours of total engine operation in various modes, excluding long-term operation with maximum efficiency. Simple calculations show that 400 hours of engine operation in the city at an average speed of about 25 km / h correspond to a mileage of 10,000 km. And the same hours of movement outside the city with an average speed of 60 km / h - this is already 24,000 km, although it is doubtful that it is necessary to delay the replacement so much.

Not all car owners have had the opportunity to drive exclusively on freeways, and even slowly. What to do for those who travel mainly around the city and also have a car with a boosted engine. Looks like shortening oil change intervals.

What type of engine oil is used also has a significant effect on the frequency of replacement.

Properties of motor oils

A huge selection of this consumable in stores often confuses the car owner and makes him ask the seller a rather stupid question - which one is better? But they are not divided into good and bad, they are all designed for different types of engines. For example, what is suitable for a diesel engine is not suitable for a gasoline engine, but this does not mean that it is worse.

Any oil consists of a base and additives added to it. Types of bases:

• mineral;
• semi-synthetic;
• synthetic;
• synthetic hydrocracking.

Minerals are extremely rare today. They were replaced by semi-synthetic ones, with a higher content of additives. Their basis is not resistant - the products of its decay greatly pollute the engine. Additives are also not very secure. And the viscosity changes significantly with time. Despite all this, the stability of this basis is enough for the recommended 10 - 15 thousand kilometers. But under more difficult operating conditions, this interval should be reduced.

Oils with a synthetic hydrocracked base are considered ordinary semi-synthetics, but they are much better, since their viscosity is more stable and additives are retained more reliably. Most of the oils from automakers are made on this basis. Even at high mileage, they perform better than their mineral-based competitors. They have less harmful decay products and better cleaning properties.

Types of classifications

• SAE - viscosity classification;
• API - classification by purpose and quality.

The SAE class indicates the temperature range in which the oil allows the crankshaft to be cranked by the starter and pumped through the lubrication system without dry friction.

Winter classes:

Summer classes:

• 20 - min viscosity at 100°C 5.6 mm2/s;
• 30 - min viscosity at 100°C 9.3 mm2/s;
• 40 - min viscosity at 100°C 12.5 mm2/s;
• 50 - min viscosity at 100°C 16.3 mm2/s;
• 60 - min viscosity at 100°C 21.9 mm2/s.

All-weather are designated by two numbers, one winter class, the other summer, for example: SAE 5W-30 or SAE 10W-40. Each of them corresponds to the parameters of one winter and one summer class.

According to the API, oils are divided into the following operating categories:

• S (Service) - for gasoline engines, subdivided into quality groups presented in chronological order;
• C (Commercial) - for diesel engines, subdivided into quality and purpose groups, presented in time sequence;
• EC (Energy Conserving) - energy saving: a new group of high quality oils with low viscosity, good fluidity and reduced fuel consumption according to tests carried out on gasoline engines.

Each new class is identified by the next alphabetical letter. Universal application (for gasoline and diesel engines) are indicated by two letters, the first in the designation is the main one, the second indicates the possibility of application in engines of a different type.

API quality classes

For gasoline:

• SM - from 30.11.04 for current multi-valve and turbocharged engines, the oil is protected from oxidation with improved qualities at low temperatures;
• SL - for multi-valve and turbocharged engines produced after 2000, running on lean fuel mixtures. It is acceptable to use when recommended by the manufacturer of oil class SJ and earlier.
• SJ - for engines of passenger cars, minibuses and light trucks after 1996 release. Oils of this class can be used with recommendations of class SH and earlier.
• SH - for engines manufactured after 1994.
• SG - for engines produced after 1989.
• SF - for engines manufactured after 1980.
• SE - for engines produced after 1972.

For diesel:

Consequences of exceeding the service life of the oil

In cases of significant exceedance of the terms of operation of semi-synthetics or synthetics in the engine, coking occurs on the pistons, leading to loss of mobility of the rings, a drop in compression and increased wear of parts of the piston group, as well as an increase in oil consumption due to the occurrence of rings.

When determining the intervals for changing engine oil, we are guided by the manual.

The interval for changing engine oil is always specified by the manufacturer of your car. in the manual (manual) or in the service bulletin (Service bulletin). As a rule, the manufacturer indicates the engine oil change interval in kilometers (or miles). There are also restrictions in the time period - 3 months -6 months - 1 year. The car can stand in the garage all winter and not go out on the road, and the oil in the engine will still lose its original properties - that is why the manufacturers have also introduced a temporary restriction. You can’t conclude “I roll on the mileage very little, so I will change the oil every 2 years.”

Deciding for yourself how often you change the oil, not based on the manufacturer's recommendations, is not right! Only the manufacturer of your vehicle, who designed and built your vehicle, knows better How often should the oil be changed? The car manual is a kind of bible, when making decisions, you should always look back at this document. Remember, your car was designed and built by thousands of engineers and specialists, they have already calculated and tested everything for us - there is no need to consider yourself smarter than VW or Toyota and reinvent the wheel. It is necessary to adhere to the manufacturer's recommendations as much as possible!

Rely on the manufacturer, but don't make a mistake yourself ...

But the manufacturer must also be able to interpret correctly! Recently, manufacturers have begun to increase the service intervals for changing engine oil. For the sake of economy, ecology, restrictive legislative acts of some countries, oil change intervals have increased markedly 30,000 km, 50,000 km, etc.

There are special "long-lived" oils for extended oil change intervals "LongLife". But such oils can only be poured with extended drain intervals into engines that are suitable for this! You can’t conclude “If I fill the VAZ Kalina with Longlife oil, then you can not change the oil for 30,000 km.” Kalina's engine will kill such oil much faster!

Extended oil change intervals are relevant for countries with a "mild" climate, with good fuel quality, with clean roads, high-quality oils, and timely service. In severe vehicle operating conditions - such extended change intervals can lead to premature aging of engine oil and engine wear!

For example, when you try to start the engine at -30C, fill the crankcase with gasoline and eventually do not start, the oil liquefies, loses its properties under the influence of gasoline, and the manufacturer does not take this into account. You can drive 30,000 km on such spoiled oil and then guess where the wear comes from.

Example: In the list of approved Longlife-04 oils, BMW writes:

The use of Longlife-04 oils in gasoline engines is only permitted in European countries (EU plus Switzerland, Norway and Liechtenstein). Outside this region, their use is prohibited due to the often questionable quality of the fuel.

Link to official document: BMW Longlife-04 approved oils. That is, these oils are not suitable for Russian conditions, taking into account the extended change intervals!

What is severe operating conditions?

Severe operating conditions include:

1. Poor fuel quality. Fuel never burns out completely. During the combustion of fuel in the engine, combustion products are formed - ash, soot, tar, sulfur, etc. Deposits form on the inner walls of the engine - soot, sludge, varnish, etc. The worse the quality of the fuel, the more deposits and unwanted combustion products. Engine oil wears out faster! Russian oil already initially considered to be of lower quality due to the high sulfur content, as well as heavy and cyclic hydrocarbons. To this we must add the peculiarities of the "Russian business" and the lack of strict control over the production and sale of fuel. The quality of fuel constantly jumps from refueling to refueling. Production of gasoline from 76th to 92nd by adding additives. Water condensate, sand, dirt in storage and transportation tanks, etc. All this affects the resource of engine oil! Therefore, at least somehow to protect yourself from these negative factors, it is possible only by gas stations at trusted gas stations And frequent oil change intervals! It is frequent oil changes that help to remove unwanted products from the engine, neutralize sulfur from burnt fuel, slow down oxidative processes, etc. No "super-long life" LongLife oil or PAO-synthetic with long drain intervals can miraculously remove all this from the engine.
2. Trips over short distances. On short trips over short distances, the engine does not have time to warm up. Engine oil does not have time to warm up to operating temperature. Additives that neutralize the products of combustion of fuel work more slowly due to the slowdown of chemical processes in a cold engine. Low-temperature deposits are formed that clog the filter elements and impair the circulation of oil through the lubrication system. Operation of the engine in the "started - drove 5 km - turned off" mode leads to the transformation of the condensate formed on the inner walls into water. Water in the oil leads to oil flooding - premature "aging" of engine oil.
3. Dusty roads, or roads that are treated with anti-icing agents. The air filter does not capture all dust particles - a small amount still gets into the engine. It is also not uncommon for unfiltered air to enter the engine through a poor quality filter, an abnormal air leak (the air hose cracked, the gasket became numb), etc. When operating the engine in dusty conditions, dust particles accumulate during engine operation, cause abrasive wear of parts and reduce the anti-wear properties of the oil. In simple terms, dust and sand enter the cylinder-piston group and, of course, this does not bring anything good.
4. Traffic jams, long trips at low speeds, long “downtime” at idle. Constant acceleration and deceleration in traffic jams load the engine the most, the oil is used up faster. At idle (XX), the oil pressure in the system is several times lower than at full speed - the oil enters the engine components, not as well as it does at full speed along the highway. The same happens with long trips at low speed. For example, on a dirt road "where you can't really accelerate." The load on the engine is large, and the engine oil does not flow abundantly. The engine at idle (XX) is poorly washed with oil, as a result of which, again, rings can lie down, deposits can accumulate on the walls of the engine. The owner of the car at this time calmly looks at the odometer, where the cherished 15,000 km have not yet arrived and convinces himself that "everything is fine!".
5. Operation in conditions of extremely high or extremely low ambient temperatures. When operating a car in the summer heat, the engine is exposed to high temperatures, the oil heats up, and therefore the oil film becomes thinner, the coefficient of friction increases, and the oil film on the surface of the friction pairs may break. If we add to this the towing of a trailer, and even high speeds along the highway, we get a very tough regime. Remember yourself, on a trip to the South, during the holidays - we will load the whole family, pick up a trailer and "spear" at high speeds along the highway - it would be faster to get to the sea / or back home. This is just the case! High air temperature also accelerates the oxidation processes in the engine and affects the development of the engine oil resource. Operating the engine at low temperatures also affects the life of the engine oil! Attempts to start the engine in cold weather often result in the engine not starting while fuel was being supplied. Settling in the crankcase, the fuel enters the engine oil and dilutes it. Subsequently, the fuel, of course, burns out and evaporates, but the oil has already been spoiled and, in a miraculous way, cannot be restored to a fresh state. In winter, we often warm up the engine before we start driving, but long periods of idling (XX) are again not good for engine oil. The engine is running - but the car does not “wind up” the mileage, meanwhile we change the oil according to the mileage!
6. Towing a trailer, transporting heavy loads in the trunk, operating a car in mountainous areas. It's not a secret, in heavy-loaded equipment, oil depletes its resource much faster. If you uproot stumps in the country with your car, you will wear out the motor ten times faster than during normal operation. The more the engine is loaded, the faster the oil wears out in it. The operation of a car in mountainous areas, where there are frequent ups and downs, also seriously affects the reduction of engine oil life.

It is generally accepted that in Russia there are difficult operating conditions! On our resource, the site has repeatedly seen examples and confirmations that the Japanese in Japan, Europeans in Europe, Americans in the USA consider their “greenhouse” operating conditions to be difficult and reduce shift intervals by half! Then what are the operating conditions we have in Russia?

On-board computer as a guideline for oil change dates.

In modern cars, the on-board computer, based on the data received, itself signals when to change the oil. The service interval (mileage until the next maintenance) is calculated from the distance traveled over a certain period of time, the fuel consumed and the temperature change over the same period. Data is collected from various sensors in the car, crankshaft speed sensor, oil temperature sensor, distance traveled from the tachometer, fuel consumption, etc. Based on this data, the control unit calculates the remaining mileage until maintenance and signals the required service interval on the display.

Fig 2. An example of how the service interval is calculated in Skoda cars:

Fig 3. Depending on the received data, the on-board computer may issue various options:

But you need to understand that the on-board computer is just a machine, which does not take into account many factors, and was created by its manufacturer, which cannot take into account all factors either! Therefore, you will not make it worse if you change the oil more often - you will only make it better!

So after all, what engine oil change interval should I choose?

Let's highlight the main points when choosing an engine oil change interval.

1. Look at the manufacturer's manual. It is the manual, and not translations of third-party Russian publications, taken from nowhere! In the manual we find a plate with shift intervals, and the lines "under severe operating conditions, we recommend halving the shift interval." Sometimes there is nothing in the manual about mileage. We are looking for official technical documents, usually they are in English. Be sure to follow the official recommendations of the manufacturer of your car!
2. We define our operating conditions. In most cases, if you live in Russia, you have a difficult operating conditions! But there are exceptions! For example: You live in a quiet, provincial town, where there is no traffic jams. The climate is temperate, the temperature in summer is not more than + 30C, in winter there are no frosts. The car is operated daily and travels at least 20-30 km after starting. The car does not idle XX for 20-30 minutes (you do not use the auto-start function of your alarm - yes, this is also harmful!). You fill up the fuel at one gas station, you know for sure that it is of good cleaning, with a low sulfur content. Fuel is supplied directly from the refinery, all documents are in order (and in general this is your relative's gas station 🙂). The terrain is flat, not dusty, the roads are paved (because the president recently came to your city 🙂). In these cases, you can not shorten the shift interval and consider that you have normal operating conditions! In all other cases, consider your operating conditions as severe!
3. What oil are you using? If you pour mineral oil, it lives less - you need to make discounts for this. The same applies to "synthetic" oils based on hydrocracking (VHVI, Group III). If you pour real PAO / Ester synthetics - they last longer than mineral oils and hydrocracked ones - but don't flatter yourself! In engine oil, in addition to the base oil, there is a package of additives that work out, regardless of whether they are dissolved in synthetics or in mineral water. If you have severe operating conditions, you need to pay attention to the characteristics of engine oil. On oils with a low base number (for example, TBN = 5-6), as well as on poor high-sulfur fuels, it is not advisable to drive with long shift intervals!
4. What engine do you have? If the engine of your car is equipped with a turbine, the oil wears out faster than in a simple atmospheric engine. There are manufacturers who recommend in difficult conditions, for turbo engines, the change period is 2500 km!

Example 1: Let's try to decide on the change interval for a 2008 toyota camry.
We find Toyota white paper:, below in small text is written "In severe operating conditions, reduce the shift interval by two." We divide 14000/2=7000km. Final Choice: Change interval 7000 km.

What do motor oil manufacturers say?

Motor oil manufacturers almost always stand in solidarity with automakers when it comes to change intervals. Almost everywhere it says "Consult your vehicle owner's manual." But there are expert answers in the form of advice. In their responses, motor oil manufacturers almost always rely on the recommendations of automakers!

In conclusion of the article, I would like to quote FAQ, a very famous and popular in the West, motor oil manufacturer - Valvoline.

Question: Do I need to shorten my oil change interval to 3000 miles (about 5000km)?
Answer: Valvoline recommends changing the oil every 3000 miles (about 5000km). The majority of motorists (more than 80% of drivers, according to a California study) operate the car in severe operating conditions (start-stop mode, short distance driving, towing, very high or very low temperatures, etc.) Automakers recommend reducing shift intervals in heavy operating conditions, most recommendations are 3750 miles or less, with 3000 miles (about 5000km) being the most common recommendation. Engine oil and oil filters have a shorter life in severe operating conditions, due to the increase in the amount of contaminants. Thus, changing the oil and filter every 3,000 miles (about 5,000 km) is the best way to ensure a healthy engine.

You can subscribe to every word! It is the frequent intervals for changing engine oil - 5000 km, that will protect you from the accumulation of deposits in the engine, from the negative effects of poor quality fuel, from harsh vehicle operating modes, etc. Shortened engine oil change intervals, one of the most effective ways to keep your engine in top condition! With change intervals of 5000 km, the car's engine will serve faithfully for many years!

Motors consume not only gasoline, but also oil. And you want to save money on it. Can last year's oil work for another season?

Car manufacturers recommend changing the engine oil every 15 thousand kilometers. Standard operating conditions allow you to ride on one fill for a year. But the operation of the machine in a metropolis differs markedly from standard conditions and involves increased loads on all technical units. Therefore, oil change times are reduced.

On the one hand, in a large city, runs are small, only 30-40 kilometers on weekdays. But if, on free roads, a car flies through them in 20-30 minutes, then at rush hour the path stretches for a total of 3-4 hours to work and back. Traffic congestion forces you to push through the crowded streets in first gear, repeating the cycles of starting and braking an infinite number of times. And the engine burns fuel all this time, spinning up to 3000 rpm and dying again. Naturally, the temperature rises, the air conditioner takes a lot of energy to run the compressor, and the engine overheats.

Even worse, when the owner of the car, in order to save money, got used to pouring cheap AI-92 instead of AI-95 gasoline, which is reflected by an increased number of detonations. Then the temperature regime of the motor goes beyond the established limits and another overwhelming task falls on the oil: cooling of local overheating zones.

In general, traffic in traffic refers to extreme operating conditions and not only reduces the life of the mechanics, but also affects the life of the oil. And, in order to determine the service life of the oil, it is necessary to consider it not in mileage, but in engine hours, as on special equipment.

Make it simple. Usually, in passenger cars, 200-250 hours of engine operation are generated per 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 stand in traffic jams longer, and their motor still does useful work. Therefore, an oil resource of 200-250 hours is produced in Moscow for 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 experience a shortage of good lubrication. And this is dangerous for technology, since modern synthetic oil is very afraid of overheating. Its additives change properties under the influence of 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, then burnt oil will drip like water. Then a direct road to the store for a new canister.

In general, it is better not to save on oil and replace it at least before the summer season. If the warranty car is pushed in traffic jams every day and rolls over 8 thousand kilometers a year, then it is better to call at specialized technical stations to change the oil twice a year. In this case, it is necessary to fill in only the oil that is recommended by the manufacturer for a particular model. It is selected based on the temperature conditions of the engine.