Many people believe that vehicle inspections are carried out exclusively during maintenance. You can’t argue with this, but what to do during the period post-warranty service. When to implement such important procedure How to change the lubricant in the engine? On this score, you can hear different answers among car enthusiasts. From the usual seasonal ones in the form of “I’ll replace them when summer or winter comes,” to the classic “I’ll wait for the required odometer reading.”
Official answer: after how many kilometers should you change the oil in a car engine?
The main regulatory body under the hood of a car is oil dipstick. It is by looking at it that we ensure compliance with the main rule - the oil fluid level must be maintained between Min marks and Max. You can also notice the following trend: the lubricant darkens as it is used. This happens due to contamination by fuel combustion products. Therefore, the lubricating emulsion is not eternal; after a certain period it must be changed.In the classic version, the operating book prescribes at what mileage to change the oil in a car engine. Typically this figure varies between 13,000-15,000 km. It is worth noting that the value was chosen for ideal load conditions:
- Clean motor.
- Average speed.
- Work without overheating.
This mode is achieved at an average speed of at least 50 km/h, which is ensured when driving on country roads over long distances. 
Is it worth deviating from the manufacturer's requirements?
In most cases, yes. Here is the list harsh conditions work for motor lubricant that require routine maintenance more often:
- Driving on mountain roads.
- Traveling in dusty areas.
- Frequent trailer towing.
- Increased ambient humidity.
- Severe frosts and constant temperature changes.
For these reasons provides for completing the accessories with a canister of oil composition.
Real numbers or how long does it take to change the engine oil?
Recently, there has been more and more talk about the dangers of such a regime as moving in traffic jams. With such operation, the emulsion in the crankcase quickly deteriorates. This occurs as a result of contact of the composition with unburned fuel and crankcase gases.
Let’s add here the lack of proper cooling of the container and we get optimal conditions for lubricant oxidation. This is an undesirable phenomenon that directly causes the aging process. In addition, on low revs the lubrication conditions for the CPG worsen. This means that all wear products will soon end up in the crankcase area.
During the entire period of use, car oil goes through several states. They can be conveniently configured into three groups. On this basis, it is convenient to note how long it takes to change the engine oil in order to preserve its factory service life during mixed city/highway operation:
- Clean (up to 7,500 km) – ensures preservation perfect condition motor.
- Working (8-15 thousand km) - contaminated liquid, which has naturally aged and lost a number of its properties (undesirable status - negatively affects the power plant).
- Emergency (over 15 thousand km) - guaranteed clogging of the oil system, emergency mode friction and, as a result, extreme wear of components.
"Traffic" cars
For each machine, the period for changing the lubricant is selected individually. This is absolutely logical and directly depends on the conditions in which the car is used. For example, with a weekend car everything is clear. It is used mainly over long distances. Engine performance is close to optimal - no questions asked. Change it in accordance with the service book and there will be no problems.
Important! Even if the car just sat for a year with a new emulsion or drove, say, a couple of thousand kilometers in 12 months, the lubricant must be changed without reservation. Oil is a chemical, and chemical compounds they degrade from stagnation.
The situation with the city employee’s car looks much more complicated. The vehicle travels no more than 20-30 km per day. Average speed – 20 km/h. main feature – power point works uninterruptedly for several hours, it forms and in the combustion chamber. Agree, in 3-4 hours you can travel much more on the autobahn than in traffic jams.
In this state of affairs, being guided only by odometer readings is incorrect and dangerous: the emulsion will not withstand 15,000 km. Here it is worth focusing on the mileage on the roads large city change the oil in the car engine. So, to ensure the factory resource, the figure shown by the computer must be divided by 2.5-3. In other words, changing every 5,000 km oily liquid in the engine when operating within a metropolis, one can hope for the longevity of the device.
The concept of motor resource
All conversations translated into mileage terms are approximate. The most accurate answer in this matter is given by engine hours. Based on the total operating time of a diesel or gasoline engine, it is impossible to miscalculate the timing of routine maintenance on the engine.
Determining the red limit is simple: just estimate how long it will take the car to cover the official 15,000 km at an average speed of 50 km/h. The answer is immediate – 300 hours. We take this figure as the change point. At the same time, do not forget about the mileage - it is strictly not recommended to exceed 15,000 km.
Technically, solving the problem of measuring the operating hours of a power unit is not difficult. It is enough to purchase an engine hour meter: either electronic or electromechanical. It cuts into any operating circuit that is activated by the ignition switch. It remains to fix the device in convenient location and installation is completed. There is no need to be afraid to disconnect the battery – the gadget’s memory is non-volatile. 
Theoretical option
An alternative to the odometer and engine hours is the amount of fuel burned. We calculate how many liters will be consumed per 15,000 km at individual average consumption, which is shown by the BC. So, the answer to the question, after how many liters of burnt fuel should you change the oil in a small car engine, is this - every 1,000 liters. However, you will have to work hard to ensure that all fuel receipts are collected and processed.
The lubricant in the engine should be changed based on the operating conditions of the vehicle:
- 5-7 thousand km: 95% of the time – driving through traffic jams in a cramped metropolis at an average speed of no more than 20-30 km/h.
- 13-15 thousand km: 70-80% of the time – driving on the highway.
- Every year, regardless of mileage: the oil begins to age after the plug is opened.
The most accurate method for determining timing routine maintenance– recording engine hours using a meter. The red limit is 300 units. An alternative technology is to count the number of liters of fuel burned.
As a rule, most car enthusiasts adhere to the service schedule, according to which every 10 or 15 thousand km. However, not everyone takes into account whole line operating features and other nuances that can significantly reduce oil life.
In practice, engine oil can lose its properties by 5-7 thousand km. mileage It turns out that if replacement is prescribed at 15 thousand and the driver is guided only by this indicator, then the engine will have the remaining 7-8 thousand km. will work for wear, the overall performance of such a unit will be greatly reduced.
Next, we'll talk about when to change your engine oil based on certain factors, whether you should change based on mileage alone, and how quickly the lubricant works depending on what type of product you're using (, mineral oil etc.).
Read in this article
Changing engine oil: by engine hours or mileage
Let's start with the fact that mileage is a fairly arbitrary indicator. In other words, for the life of the oil big influence renders:
- operating mode vehicle;
- the quality of the lubricant itself;
It turns out that the lubricant life directly depends not only on the mileage, but also on the conditions in which the car is operated, as well as what kind of oil is poured into it. These features together determine the intensity of lubricant aging.
So, let’s note right away that it would be wrong to change the oil only based on mileage. The fact is that each car is operated individually. One car can constantly drive exclusively on the highway, the engine often spins up to high and maximum speed, while another car constantly moves around the city at low speed, sits idle in traffic jams, the engine often idles for a long time, etc.
If in the first case everything is more or less clear, then the second one needs to be considered separately. Please note that although the mileage may be low, if you count the engine hours that the engine has worked on filled with lubricant while driving around the city, it turns out that such oil has still “worked out”.
Otherwise, the same mileage on the highway and in the city when converted to engine hours may differ by 3-4 times. In numbers, it looks like this: if you change the oil every 15 thousand km, in highway conditions the lubricant will work no more than 250 hours. At the same time, 15 thousand km. mileage in the city is around 650-700 engine hours.
To this it should be added that modern engines are quite “hot”, that is, they open at high temperatures, problems often arise, the engine does not cool well when idle in a traffic jam. All this also greatly accelerates the aging process of engine oil.
When driving on the highway, it’s not so simple either. The fact is that the load on the engine can differ significantly. If the driver drives at a speed of 110-120 km/h, then the load is power unit average or even lower, the internal combustion engine cools well, the crankcase ventilation works fully during such driving. Under such conditions, the load on the oil is small.
Engine oil viscosity, what is the difference between oils with a viscosity index of 5w40 and 5w30. Which lubricant is best to pour into the engine in winter and summer, tips and recommendations.
It should be noted that changing engine oil based on mileage is almost always a suboptimal solution. Even if the mileage in the city or in highway mode is the same, it will still be approximately a fourfold difference in engine hours. An equally significant difference will be observed in the deterioration of the properties of the oil. For example, if, with the applied oil change interval of 15,000 km, the oil lasts about 700 hours in traffic jams, then on the highway it lasts less than 200 hours.
Oil change: by mileage or time?
Speaking about the quality of oil performance, such a difference is considered quite large, since in an engine operating at low loads, the oil has an increased thermal effect. In addition, modern engines aggravate the situation, because the temperature control in them is high, crankcase ventilation is not always sufficient, and there is practically no cooling of a car standing in a traffic jam, which affects sharp decline its resource.When moving along the highway, the load values may be different. So, at speeds of about 100-30 km/h, many cars will have an average load on the engine, the crankcase is well ventilated and the temperature is low. For motors with more power, the load is generally minimal, and accordingly, the load on the oil is also small.
If the speeds are higher, the load on the motor increases, and the load on the oil will also increase. The engine and oil feel very bad in small cars equipped with a “short” transmission. The load increases more smoothly on motors with higher power.
Simultaneously with the increasing load on the engine, the conditions in which the engine oil operates deteriorate: the temperature of the pistons becomes higher, the flow of harmful crankcase gases starts to grow. We can conclude that for both the engine and the oil, the optimal operating mode is medium speeds and shorter operating time after warming up at idle.
Calculating engine hours, it turns out that the usual 15,000 oil change interval in engine hours will be 200-700. It all depends on the driving modes. For example, if we take BMW as a starting point, assessing the scheduled mileage using their meters and the oil change intervals indicated on the vehicle, this manufacturer indicates the replacement time in engine hours. Therefore, change the oil when different modes operation, will be needed after 200-400 hours, excluding permanent job motor at maximum power.
It is noteworthy that 400 engine hours in the city, where speeds are usually about 25-30 km/h, are therefore equivalent to 9-10 thousand kilometers from oil change to oil change. But 400 engine hours, which passed at a speed of about 80 km/h, give over 30,000 unrealistic kilometers, but you should not strive for such an indicator at all.
conclusions
Few car enthusiasts can boast constant speed when using your car in suburban cycles. So what to do if city runs predominate, and the engine in the car is forced? The answer is quite simple - you need to change the oil more often. But it’s not just the driving mode that affects the replacement interval. An important role is also played by the oil poured into the engine.General instructions
At the same time with technical maintenance given frequency necessary carry out all operations required for daily maintenance.
Frequency of changing engine oil and oil filter
The logic diagram on the next page will help you determine maximum oil and oil filter change interval in kilometers and miles driven or in engine hours or months of operation, whichever comes first.
*Depends on what comes first. If your vehicle accumulates many engine hours with a small number of kilometers, then the frequency of oil changes is measured in hours.
Motor oil and oil filter
Replacement
Attention! To avoid skin and other diseases, avoid prolonged or frequent contact with used motor oil.
If soiled, rinse thoroughly.
Keep out of the reach of children.
ENVIRONMENTAL PROTECTION: Handling of used motor oils is regulated by federal and state laws and local government regulations. For questions regarding the collection and disposal of used oil, please contact organizations and enterprises that have permission to do so and have special equipment and capacities. For advice on these issues, please contact your local government environmental committees.
NOTE: If the engine is in operation, then the frequency of oil changes must be 10,000 km or 250 engine hours or 3 months of operation (or the frequency determined for your engine according to the diagram on page 4-3).
When changing the oil, you should also replace the oil filter to avoid contamination of the fresh oil.
NOTE: The oil must be drained when it is hot, when contaminants are in suspension.
Key 17 mm
Attention! Hot oil can cause burns.
Run the engine until the coolant temperature reaches 60°C.
Wrench 90-95 mm for removing filters
Clean the oil filter connection area from dirt and remove the filter. Wipe the filter mating surface.
NOTE: The O-ring may rub against the filter head. Be sure to remove it before installing a new filter.
Check and make sure the correct oil filter is used.
Filter for six-cylinder engine longer than the filter for a four-cylinder engine.
A = filter size for four-cylinder engine
B = filter size for six-cylinder engine
Attention! A 6-cylinder engine oil filter can be used on a 4-cylinder engine, but not vice versa: using a 4-cylinder engine oil filter on a 6-cylinder engine will cause engine damage.
NOTE: Fill the filters with clean engine oil before installing them on the engine.
Before installing filters, apply a thin layer of engine oil to the mating surface.
Attention! Over-tightening may damage the threads or seals.
Install the filter in accordance with the manufacturer's instructions.
Key 17 mm
Check and clean threads drain hole, plugs and sealing surface.
Reinstall the drain plug.
Tightening torque: 80 N*m
NOTE: For CUMMINS engines use high quality oils with a viscosity of SAE 15W-40, such as, for example, Cummins Premium Blue, or any others of similar quality. Section V of this manual provides recommendations for the use of motor oils in specific climatic conditions.
Fill the engine crankcase with clean engine oil to the required level.
4 cylinder 6 cylinder
Oil pan capacity 9.5 l 14.2 l
Total system capacity 10.2 l 15.1 l
NOTE: Capacity is based on a standard pallet. The entire system includes a standard pan and filter.
On some 6-cylinder CUMMINS engines Series B uses pallets with a smaller capacity of 10.4 liters, and on some - with a higher capacity of 16 liters. Filling the crankcase with oil necessary produce according to pallet capacity
Let the engine idle to check for oil leakage from the filters and through the drain plug.
Stop the engine. After waiting 15 minutes for the oil to drain down, check the oil level again. If necessary, add oil to the upper “H” mark on the level indicator.
Air intake system
Inspection
Inspect the air intake system for damaged hoses, loose clamps, or other problems that are causing unclean air to be drawn in.
Correct any faults when found, ensuring the system is sealed.
Air cooler charge air
Inspection
In case of interruptions in the operation of the turbocharger or other malfunctions associated with the ingress of contaminated air, it is necessary to clean the air cooler.
Remove the coolant from the vehicle it comes with. Next, proceed in accordance with the vehicle manufacturer's instructions.
Inspect the air cooler for cracks, tears, or other damage.
Check tubes, fins and welds for tears, chips or other damage.
The procedure for checking for leaks is outlined in Section A.
Cleaning
Use solvent to flush the inside of the cooler in the direction opposite to the normal charge air flow. Shake the cooler and lightly tap it with a rubber mallet to help remove any accumulated dirt. Continue rinsing until complete removal from the cooler of all contaminants.
Attention! Caustic cleaning agents should not be used to clean the air cooler as they may cause damage.
After thoroughly cleaning the cooler with solvent, removing oil and contaminants, wash the inside of the cooler with hot soapy water to remove any remaining solvent. Then rinse thoroughly with clean water.
To dry an air cooler, you need to direct a stream of compressed air into the cooler in the opposite direction to the normal air flow. Dry until dry.
The procedure for installing the air cooler is described in the vehicle manufacturer's instructions.
Air purifier
Examination
The maximum permissible resistance in the air intake system for turbocharged engines is 635 mm water column, and for naturally aspirated engines 510 mm water column.
When checking resistance in the air intake system, the engine must be running at full load at rated crankshaft speed.
If the resistance reaches the maximum limit, the air cleaner filter element must be replaced or cleaned according to the manufacturer's instructions.
NOTE: Clean or replace the air cleaner filter element in accordance with the manufacturer's instructions.
If your air cleaner has a dust indicator, monitor its readings.
Replace the filter element if the red indicator (2) closes the window (1).
After replacing the air cleaner filter element, return indicator to the starting position by pressing button (3).
NOTE: Do not operate a Cummins engine without an air cleaner filter element to prevent dust from entering the engine, causing premature wear.
Many car owners do not know how often to change the oil in their car’s engine 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 entirely true.
It's better be guided by the number of engine hours worked and the average speed. There are many components to the answer to the question of how often to change engine oil. Among them are the recommendations of the car manufacturer, operating conditions of the car (heavy/light, in the city/on the highway, often/rarely used), mileage before changing the oil and total mileage, technical condition car and the oil used.
Also, the frequency of engine oil changes is influenced by additional factors - the number of engine hours, engine power and volume, time last replacement oil (even without taking into account the operation of the machine). Next, we will tell you in detail about how often to change the engine oil, what it is like, and other things that will probably 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 regarding the change interval: in urban conditions, the oil “works” for 8-12 thousand, on the highway/light driving mode without traffic jams it lasts up to 15 thousand km. The most accurate way to find out when to change can only be given by laboratory analysis oil waste.
What affects the replacement frequency
Each car manufacturer indicates in the car manual detailed information about 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 reality, several factors influence the mileage between replacements.
10 indicators that affect the timing of engine oil changes
- Type of fuel (gas, gasoline, diesel) and its quality
- Engine capacity
- Brand of previously filled oil (synthetic, Semy-Synt, mineral oil)
- Classification and type of oils used (API and longlife system)
- Engine oil condition
- Replacement method
- Total engine mileage
- Technical condition of the car
- Operating conditions and modes
- Quality of consumables
The manufacturer's instructions are not included in this list because they service interval– a marketing concept.
Operating modes
First of all, the timing of engine oil changes is affected by car operation. Without delving into the essence of the various transient processes, 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 accumulates much faster, and secondly, normal cooling of the engine occurs. Accordingly, the load on the engine and 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 stops at traffic lights and traffic jams with the engine running. The cooling will be insufficient.
In this regard, it would be more accurate to calculate how long it takes to change the engine oil, based on engine hours, as is done in cargo, agricultural and water equipment. Let's give an example. The car will travel 10 thousand kilometers in urban conditions (at an average speed of 20...25 km/h) in 400...500 hours. And the same 10 thousand on the highway at a speed of 100 km/h - in only 100 engine hours. Moreover, the operating conditions of the engine and oil on the highway are much milder.
Driving in a metropolitan area is rightly equated to driving on rough off-road conditions 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 less minimum level. Also remember that in hot summer weather the oil is subject to a much greater load due to high temperatures, including from the hot surface of roads in big cities.
Engine size and type
What affects the frequency of oil changes
How more powerful 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 impact. For powerful motor driving along the highway at a speed of 100...130 km/h does not exert a significant load, it will be below average. As the speed increases, the load on the engine, and therefore on the oil, will change smoothly.
Small cars are another matter. As a rule, they are equipped with a “short” transmission, that is, the gears are designed for a small speed range and operating speed range. Respectively, small engines experience greater loads in critical modes than powerful ones. When the load on the engine increases, the temperature of its pistons also increases, and the amount of crankcase gases also increases. This leads to a general increase in temperature, including oil temperature.
It’s especially hard for small-displacement forced engines (for example, 1.2 TSI and others). In this case, the load is also supplemented by a turbine.
Additional factors
This should include high temperature temperature control (operating temperature), poor ventilation of the engine crankcase (especially when driving in urban conditions), use of poor quality or unsuitable of this engine oil, presence of dirt in the oil channels, clogged oil filter, working temperature Range oils
It is believed that optimal interval engine oil changes range from 200 to 400 operating hours at various modes operation except maximum load, including driving 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 types separately using the links provided.
Why do you need regular oil changes?
Indication on the dashboard
What can happen to a car if you don’t change the engine oil for a long time? To answer this question, you need to understand what functions it performs. Any oil consists of a so-called “base” and a certain amount of additives. They are the ones who protect engine parts.
During the operation of the machine, and even its parking, continuous chemical destruction of additives occurs. Naturally, this process is faster when driving. In this case, natural deposits form on the engine crankcase, oxidation processes occur with individual components of the oil, its viscosity and even the pH acidity level change. These facts are the answers to the question - Why change the oil once a year at least?.
Some automakers and motor oil manufacturers indicate how long it takes to change the engine oil not by mileage, but by frequency, usually by month.
And under significant load, the described processes in the oil occur with still higher speed. Especially at high temperatures. However modern manufacturers constantly improve technology and chemical compositions their oils. Therefore, they are able to withstand pollution and high temperatures for a long time.
In many modern cars The ECU constantly monitors when to change the engine oil. Naturally, this decision is made on the basis of empirical methodology. It is based on actual data - average engine speed, oil and engine temperature, number of cold starts, speed mode and so on. In addition, the program takes into account errors and technical approvals. Therefore, the computer only reports the approximate time when you need to change the engine oil.
Unfortunately, on store shelves not only Russian Federation, but also in other CIS countries, a large number of low-quality or simply counterfeit motor oils are currently 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 kilometers to change the engine oil, then the recommended amount should be reduced by about a third. That is, instead of the often recommended 10 thousand, change it after 7...7.5 thousand.
Change the oil AT LEAST once a year, regardless of whether you drive the car or not.
Let's list the causes and consequences untimely replacement engine oil:
- Formation of sediments. The reasons for this phenomenon lie in the process of destruction of additives or contamination of the oil with combustion products in the engine crankcase. The consequences are a significant decrease in engine power, an increase in the content of toxic substances in exhaust gases, their blackening.
- Significant engine wear. Reasons - oils lose their properties due to changes in the composition of additives.
- Increasing oil viscosity. This can happen for the same reasons. In particular, due to oxidation or disruption of polymerization of additives due to incorrect selection oils Problems arising from this include difficulties with oil circulation, significant wear of the engine and its individual elements. And the emerging oil starvation engine can lead to, in critical cases even engine failure is possible.
- Rotating connecting rod bearings. This occurs due to clogging oil channel thickened composition. The smaller the cross-sectional area, the greater the loads they are subjected to. connecting rod bearings. Because of this, they overheat and rotate.
- Significant wear on the turbocharger(if available). In particular. there is a high risk of damage to the rotor. It occurs because waste oil has a significant impact on the compressor shaft and bearings. As a result, they develop damage and scratches. Besides, dirty oil leads to clogging of the compressor lubrication channels, which can lead to 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 vehicles operating in urban environments. After all, it is considered one of the most difficult for the engine. Below we present interesting factual data that were obtained experimentally. They will help you decide at what mileage to change the engine oil.
Results of experiments with oils
Experts from renowned automobile magazine“Behind the Wheel” conducted six-month studies of several types synthetic oils under operating conditions of vehicles in city traffic jams (at idle speed). To do this, the engines operated for 120 hours (the equivalent of 10 thousand kilometers on the highway) at 800 rpm without cooling. As a result, interesting facts were obtained...
The first is the viscosity of all motor oils during prolonged operation at idle speed until a certain (critical) point significantly less than when driving “on the highway”. This occurs due to the fact that at idle speed, exhaust gases and unburnt fuel leak into the engine crankcase, where it is all mixed with oil. In this case, there may be some (insignificant) amounts of oil in the fuel.
The drop in viscosity of motor 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 normal limits. However, this only happens up to a certain point.
Clean and waste motor oils
Approximately 70...100 engine hours(each oil is different, but the trend is the same for all) 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 discussed above), and reaches its critical saturation. The mentioned products have a certain acidity, which is transferred to the oil. Lack of ventilation and low turbulization also affect air-fuel mixture due to the fact that the piston moves relatively slowly. Because of this, the rate of fuel combustion is lower than average, and the entry of exhaust gases into the crankcase is maximum.
The widespread belief is that in the regime idle move A large amount of dirt is formed in the engine, which 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 wear products, their amount is significantly greater in oil used in the “plug” mode than in the one that was used on the “highway”. The reason for this is the low speed of the pistons, as well as the high operating temperature oils (lack of ventilation). As for waste, each oil behaves differently. However, it can be argued that due to high operating temperatures and increased 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 engine oil.
Next, we will dwell in more detail on the question of how often to change the engine oil. As stated above, car manufacturers' recommendations should be taken with a grain of salt. Don't completely ignore them, but make your own amendments. If you drive your car only in city conditions (statistically, this is the majority of car owners), this means that the oil is used under heavy duty conditions. Remember that than less oil in the crankcase - the faster it ages. Therefore it optimal level- slightly lower on the indicator dipstick.
After how many thousand do you change the engine oil?
Calculation of engine hours for oil changes
We wrote above that it is better to calculate the frequency of oil changes based on engine hours. However, the complexity of this technique lies in the fact that sometimes it is difficult to convert kilometers into engine hours and get an answer based on this information. Let's take a closer look at two techniques that allow empirically, however, it is quite accurate to calculate how long after 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 (than more mileage, the more accurate the calculations will be).
So, method one (calculation by speed). To do this, you need to know the average speed of your car over the last few 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 average speed in the city - 29.5 km/h.
Accordingly, to calculate the number of engine hours, you need to divide the distance by the speed. In our case it will be 15000 / 29.5 = 508 engine 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 service life of 508 engine hours. However, in reality, such oils simply do not exist today.
We offer you a table that shows the types of motor oils and their corresponding engine hour values according to API ( American Petroleum Institute):
Let's assume that the car engine is filled with SM/SN class oil, which has a working life of 350 hours. To calculate the mileage, you need to multiply 350 engine hours by the average speed of 29.5 km/h. As a result, we get 10325 km. As you can see, this mileage is very different from what 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 engine hours we will get 7525 km of mileage! Now it becomes clearly clear why it is necessary to divide the mileage recommended by the car manufacturer 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 km according to its passport, as well as this actual value. It can be taken from the same ECU. Let’s assume that according to the passport the car “takes” 8 l/100 km, but in fact – 10.6 l/100 km. The replacement mileage remains the same - 15,000 km. Let's derive the proportion and find out how much in theory the car must spend to cover 15,000 km: 15,000 km * 8 liters / 100 km = 1200 liters. Now let's make similar calculations for actual data: 15000 * 10.6 / 100 = 1590 liters.
Now we need to calculate at what distance it is necessary to conduct actual oil change(that is, how long 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 for you an electronic calculator that will allow you to calculate the actual mileage before an oil change using the following data: theoretical fuel consumption per 100 km, actual fuel consumption per 100 km, theoretical distance to an oil change in kilometers:
However, the simplest and effective method checks - visual inspection oil condition. To do this, do not be lazy to periodically open the hood and check whether the oil has thickened or burned. Its condition can be assessed visually. If you see that 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 over a napkin. Very liquid oil forms a large and liquid stain, which will tell you that it is time to change the fluid. If this is the case, immediately go to a car service center 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 working fluid they are exposed to greater external influences. As a result, it needs to be changed a little more often. In addition, domestic diesel fuel is different high content sulfur, which has a detrimental effect on the car engine.
Regarding the readings given by the car manufacturer (this is especially true for Western manufacturers), they, similar to gasoline engines, must be divided by 1.5...2 times. This concerns passenger cars, as well as vans and small 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.
In theory, the choice of oil is based on the value of the total base number(TBN). It measures the amount of active anti-corrosion additives in the oil and indicates the tendency of their compositions 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 characterizing the oil is the total acid number(TAN). It characterizes the presence of products in the oil that provoke an increase in corrosion and wear rate of various friction pairs in a car engine.
However, before deciding how many engine hours to change the oil in an engine running on diesel fuel, you need to understand one nuance. In particular, is it possible to use motor 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 alkaline number drops, and the acid number increases. Therefore it is logical to assume. that the intersection of their graphs at a certain mileage of the car tells us that the oil has completely exhausted its service life, and its further use only destroys the engine. We present to your attention test graphs for four types of oils with different acid and base numbers. For the experiment, four types of oils were taken with conventional names of 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 up after 7000 km;
- oil B - 5W30 (TBN 9.3) - was completely used up after 11,500 km;
- oil C - 10W30 (TBN 12) - was completely used up after 18,000 km;
- oil D - 5W30 (TBN 9.2) - was completely used up after 11,500 km.
That is, the oil for heavily loaded diesel engines turned out to be the most durable. What conclusions can be drawn based on the information provided:
- A high base number (TBN) is critical for those regions where diesel fuel of poor quality (in particular, with high S impurities) is sold. Using this oil will provide you with longer and safe operation engine.
- 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.
- Similar reasoning is also 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 replacement liquids.
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 based on the value of the total acid and alkaline numbers.
conclusions
Thus, each car owner must decide for himself how often to change the engine oil. This must be done taking into account individual circumstances. We recommend that you use the calculation methods for engine hours and gasoline consumption given above (including calculators). Besides this, always visually assess the condition of the oil in the engine crankcase. This way you will significantly reduce wear on your car’s engine, which will eliminate the need to carry out expensive repairs. Also, when replacing, buy high-quality oils recommended by the manufacturer.
