Probably many people like to keep track of the mileage of their iron horse - how many kilometers there, how many there. Also, after a certain mileage, we need to carry out the necessary maintenance - for example, changing the oil, timing belt, etc. All this is monitored by a simple, but very “smart” device - an odometer. The name is unfamiliar, many have probably heard it, but don’t know what it is. I’ll try to explain, as usual, simply and in layman’s terms...
First, as usual, let's start with a definition.
Odometer - This is a device that records the mileage (kilometers) of a car. The principle is simple, it counts the number of wheel revolutions and thus displays the distance traveled, which is displayed in kilometers for Russian and many European cars, and in miles for many American cars.
As you can see, this is simply a display of mileage on the speedometers. Previously, the device was mechanical, now it is increasingly electronic or hybrid (electronics + mechanics).
How does it work?
It is important to understand how this unit works and what parts it consists of. If you don’t go into the wilds, the device can be roughly broken down into three components:
1) This is a sensor that is installed next to the wheel (there are options almost in the wheel itself), there are also options that are installed in the transmission (gearbox) - they take into account the speed in a certain way.
2) A counter or drive that counts these revolutions, then transmits them to the head unit
3) Display is a speedometer (for simple mechanical types), or an ECU that receives data and then displays it on a digital display.
I would like to note that now there are practically no mechanical odometers left, everything is moving to digital.
Device types
I propose to dwell in more detail on the types of odometer devices, so to speak, to go through history.
1) Mechanical odometers - the simplest and most easily corrected.
Typically, a sensor was hung on the gearbox, which mechanically, through a cable, transmitted information to a special unit, which in turn displayed the information on the speedometer monitor. To be honest, the reliability and reliability of the data was at a low level. Craftsmen could crawl under the car, unscrew the cable from the gearbox, and the mileage was simply not taken into account. It was also easy to remove the speedometer itself, in which the odometer was located at the bottom, and twist it by hand. So the mileage was easily adjusted in the right direction.
2) Hybrid odometers — The first electronic control units and electronic displays are already appearing here.
The design remains mechanical at the level of the drive and transmission, that is, information is obtained mechanically, after which it is converted into electronic impulses that are converted into kilometers on the odometer.
3) Electronic or digital odometers - This is a completely electronic system, starting from collecting data from drives or wheels, ending with processing (often it) to displaying it.
Such systems are the most resistant to mileage twisting; they are not so easy to adjust, because electronics are everywhere. But folk craftsmen have learned to correct them too. Usually this is the ECU firmware.
The electronic version records not only the total mileage of the car, but also the daily mileage, which is very convenient. Let’s say with a daily mileage, you can measure the distance to a particular point, and then calculate the gasoline consumption. The odometer in a car is one of the indicators of condition. Yes, yes, you heard right exactly the state. This is because the greater the mileage (kilometers) of the car that this device recorded, the more worn out the car is and must be serviced. You need to go to the station to change parts of the mechanisms, because according to the regulations, many parts of the car are changed precisely for this indication. For example, transmission oils, timing belts or chains, etc.
Reading accuracy
The odometer cannot be called an ultra-precise device; its error is significant, even with digital ones it can be 2 - 10% of the total mileage. There is nothing wrong with this - after all, the odometer does not count in millimeters and centimeters, but in tens or even hundreds of meters and kilometers. I would also like to note that the error may increase depending on the wear and tear of the car.
If we decompose the error into groups of odometers, it becomes clear:
Mechanical have the highest degree, because they have mechanical parts in each of the drive links. Even new ones have an error of 3 - 5%, but already worn ones have an indicator of about 10%.
Hybrid Due to their digital component, they cut off a large number of errors; they count pulses, and therefore the error, even with high wear, rarely goes beyond 5%.
Digital They are practically devoid of any shortcomings, they have no mechanical parts, and therefore they always take into account relatively even readings, the error even with long runs is no more than 2%.
But it’s worth noting that when a car slips, say on ice or snow, the wheel spins, a record is kept, but the car essentially stands still! So much for the error, even for electronic versions.
Twisting - odometer adjustment
First, I’ll answer why it is being corrected! Everything is very simple, the higher the mileage, the higher the wear and tear of the car as a whole, as well as important components, engine, transmission, suspension - a lot of “sores” come out. For example, many German cars will require serious financial investments after 90 - 100,000 kilometers, at least to replace the turbine and repair the robotic transmission (if we say).
Therefore, many dishonest sellers, especially resellers (persons who buy and sell cars), correct odometer readings. If it is mechanical, then everything is simple, it is simply reeled back using mechanical action. But if the odometer is electronic, then it is much more difficult to correct it, because there are no mechanical parts in it. We need special devices that can connect to the car's microcircuits. Therefore, cars with electronic odometers are more protected from adjustments. Although folk craftsmen reel them in too. Sometimes it is very difficult to understand the actual mileage, especially if the tires are new, the body is polished, the interior has been dry cleaned, etc. They may tell you that the mileage is only 20,000 km, but in fact it may already be over 120,000 km. So you need to be careful when buying a used car. Turn to professionals, even if you give him a couple of thousand rubles, but he will save you a lot of money on subsequent repairs.
Ask the first driver who gets behind the wheel what an odometer is, and he will shrug his shoulders in bewilderment, and if you ask how many kilometers you have driven today, he will confidently look at the dashboard and answer this question accurately. So, now everyone understands that an odometer is a device that measures and shows mileage, that is, the mileage of a car. The counter is located in the most visible place under the speedometer.
Photo of the odometer - a device showing the mileage of a car
Odometer, what kind of equipment is this?
The name of the device comes from the Greek words “odos” - road and “metron” - measure. Thus, the odometer must be understood as a distance meter. When applied to wheeled vehicles, this is a wheel revolution counter, through which the distance traveled is determined. The first such device was invented by the ancient Greek mechanic Heron from Alexandria.
The principle of measuring the distance traveled, based on the number of wheel revolutions, is based on the directly proportional dependence of these quantities. It is valid in the absence of wheel slipping (slipping) and a constant length of the outer circumference of the tire. Currently, in cars you can find mechanical, electromechanical and electronic models of odometers.
The most “ancient” mechanical odometers have a flexible cable that rotates at the speed of rotation of the wheel. This rotation is transmitted to the cable from the gearbox output shaft. The cable, in turn, transmits it to a mechanical drum meter located in the instrument panel. The counter has 5 reels corresponding to units, tenths, hundreds, thousandths and ten thousandths of the measured value.
The word "odometer" literally means "to measure the road"
On the end side of the drums there are evenly printed numbers from 0 to 9, which are used to count the distance traveled. The drums are connected by a worm gear with a transmission ratio of 1:10, and the cable is connected to the first drum through a gearbox with a transmission ratio of 1:1690. Thus, the mechanical distance counter will be reset every 100 thousand kilometers.
Difference in Odometer Types
Electronic-mechanical odometers differ from mechanical ones in that they have a more reliable electronic counter and indicator. The revolutions of the mechanical sensor are converted into electrical impulses, which are counted by the counter and displayed on a digital indicator in the form of kilometers traveled. Only electronic odometers are installed on cars of modern generations. They use both electronic indicators and electronic speed sensors.
Magnetic sensors operating on the Hall effect do not have mechanical contact with the differential output shaft, therefore they are more reliable and durable. Although the error of electronic types of odometers differs for the better compared to other types, this is not so important, since mileage is taken into account at least in kilometers. The fundamental difference is that electronic odometer readings are much more difficult to correct. This requires special equipment.
Equipment for adjusting odometers
When driving a car, it is often necessary to adjust the odometer readings. This is especially true for company vehicles or the use of personal vehicles for commercial purposes, where performance and payment depend on the mileage of the vehicle. And the point here is not only the desire to falsify testimony in order to obtain benefits, but also the need to maintain correct records and reporting. Indeed, often the actual performance characteristics of a car do not correspond to the passport data, on the basis of which all accounting calculations are made.
Video tutorial on how to adjust the digital odometer on a VAZ 2114
Depending on the type of odometer, you can adjust its readings in various ways. It is easiest to correct old mechanical and electromechanical meters. To do this, remove the cable from the gearbox, clamp its end into an electric drill and rotate in the desired direction until the required values are set on the meter. You can also change the counter data by disassembling the speedometer and manually setting the required drum positions using tools. Every driver can do this work with his own hands.
It is much more difficult to correct the readings of electronic odometers, which on modern types of cars are part of a single on-board computer complex. Signals from the electronic speed sensor are sent not only to the electronic odometer, but also to other on-board control systems. Therefore, depending on the vehicle configuration, you may need not only a pulse generator, but also reprogramming the on-board controllers.
The industry produces various equipment for adjusting speedometers and odometers:
- CAN speedometer winder, which uses the programmer connection to the vehicle's diagnostic CAN bus. In this case, the memory cells of all on-board devices associated with the speed sensor are overwritten. Working with this equipment requires knowledge of the communication protocol adopted in this machine model, and can only be performed by a trained specialist.
- Pulse OBDII speedometer winder, which connects a pulse generator simulating speed sensor signals to the vehicle's OBDII diagnostic connector and corrects the electronic odometer readings. This device is designed to record trip meter readings on machines not equipped with CAN buses.
- Pulse speed generator simulating a speed sensor signal. Used for winding counters of electromechanical speedometers of domestic cars produced before 2006.
- The ABS adjuster uses the on-board computer to correct the data. It sets data at the input of the on-board controller, simulating a certain speed of rotation of the wheels, and the computer begins to process odometer readings in accordance with the specified data.
- Software 5 pro, which is a new programming device for domestically produced electronic meters, as well as foreign odometers based on EEPROM microchips.
Some winding devices can be made independently. However, it is still better to buy ready-made factory-made products with detailed instructions for use, since improper use of these devices can lead to failure of all on-board electronics.
What to do if your car's speedometer shows speed in miles per hour
It seems like a small problem, that the speedometer and odometer readings are reflected in miles, and one could get used to it, however, in fact, it creates great inconvenience for the domestic driver, who is accustomed from an early age to measuring everything in meters and kilometers per hour. Especially in conditions where there are speed restrictions. Of course, you can do nothing, gradually getting used to the new reference system, but you can also reprogram the on-board equipment using the odometer correction program.
Nowadays, manufacturers of devices for flashing automotive electronics produce and improve various software designed to service various car models and installed on-board equipment.
The most well-known programs for adjusting various types of odometers are:
- speed calculator based on revolutions, which allows you to determine speed depending on gearbox gear, wheel size, crankshaft speed;
- STool program, designed to change odometer readings through the M-BUS and ELM327 diagnostic port on VAZ, Mazda, Ford, Toyota, Kia, Hyundai cars;
- VDO Corrector is a program for correcting track meters for cars of the brands Peugeot, Citroen, Renault, Sang Yong, Toyota, Kia, Hyundai, VAZ.
Odometer readings are also corrected during pre-sale preparation of the car. It is almost impossible for an uninitiated person to find out whether the meter readings have been written off. Moreover, many service station workers make a business out of this service.
At the same time, this operation does not allow for proper maintenance of the car, the frequency of which is determined by the actual mileage of the car. Therefore, to a certain extent, excessive write-off or inflation of odometer readings is a negative action that has a bad effect on the technical condition of the car.
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Which one is displayed on the odometer? Did you know that in fact, most cars' odometer readings are not entirely accurate, just like the current speed reading on the speedometer? Moreover, all these inaccuracies are deliberately introduced by automakers during the car production process. Why is this necessary and how much the odometer lies in many cars, we propose to find out in our today's topic.
Today, many motorists use navigation systems in their cars, which help us navigate unfamiliar terrain, create optimal routes and avoid traffic jams. . All modern navigation systems can determine vehicle speed. Have you noticed that the speed of your car according to the GPS/GLONASS navigator is almost always lower than that shown on the car’s speedometer?
Surely many of you think that this is an error in the navigation system. But in fact, satellite systems are much more accurate than the speedometer in a car. It is precisely because of the inaccuracy of speedometers in many cars that we see a difference in speed. But the difference in speed is also inaccurate since any satellite navigation systems also have acceptable errors. But the fact remains a fact. Almost all cars today are equipped. Moreover, this speed is always overestimated, and never underestimated.
That is, every automaker installs a speedometer that overestimates the speed readings. And this was done consciously, in accordance with various world standards. In our country, this standard is regulated by GOST R 41.39-99 (UNECE Rules No. 39).
According to this standard and technical requirements, actual speed cannot be underestimated. Also, according to GOST R 41.39-99, the speedometer cannot increase the speed by more than 6 km/h (or by more than 10%).
In practice and according to information from numerous auto forums on the Internet, we can say with confidence that most automakers equip cars with speedometers that They increase the speed on the speedometer by an average of 5-10%.
But can you tell me what the speedometer has to do with it? After all, today we are talking about the odometer. Yes, today we are discussing the topic of odometer error in a car. But the fact is that all odometers in modern cars are inextricably structurally linked with speedometer readings. Therefore, it is logical that if there is an upward error in the speedometer, then, of course, there is also an inaccuracy in the display of mileage on the odometer.
What does the mileage on the odometer turn out to be, for example, 100 thousand km. actually untruthful? Yes this is true. This is an inaccurate mileage, since it was calculated using a certain algorithm in the direction of overestimation due to the fact that manufacturers, as a rule, overestimate the speedometer and odometer readings by up to 10 percent.
As a result, it is quite possible that if you see that your car has traveled 100,000 km, then in reality the mileage is actually 95,000 - 98,000 km. It all depends on how much the speedometer exceeded the actual speed of the car during this mileage.
Why do speedometers and odometers inflate their readings?
Why are such technical requirements established for speedometers, which, in turn, affect the odometer readings? In fact, this is done for the purpose of road safety. For example, if the speedometer underestimated the speed indicators, then drivers would then believe that they were driving too slowly and would naturally, under certain conditions, increase their speed.
Also, underestimation of speed indicators would affect the number of people issued who monitor compliance with the speed limit. After all, you will agree that if the car’s speedometer showed its speed less than reality, then we would often receive fines for speeding. In this case, massive lawsuits against automakers from car owners would be guaranteed.
But this is not the only reason why automakers, on average, overestimate speedometer readings in the direction of increasing speed by 5-10%. Since the speedometer readings are directly related to the mileage on the odometer, it turns out that due to the speedometer error, the odometer incorrectly counts the car's mileage. As a result, depending depending on the operating conditions of the car (for example, on the average speed of the car) with a mileage of 100,000 km, the mileage error on the odometer can average 2000- 5000 km. Do you know what advantage this error on the odometer gives to the manufacturer? Of course, this actually reduces .
We all know that when buying a new car, any automaker gives, within 100,000 - 150,000 km of car mileage. As a result, in the event of an error in the speedometer and odometer, it actually turns out that the factory warranty ends before 100 thousand - 150 thousand. kilometers, since in reality the car traveled a little less.
Currently, most cars use an electronic odometer, which has replaced the classic mechanical odometer, which has been used for a long time in the global automotive industry. But despite the more accurate electronics, the principle of taking readings remains the same.
So, despite the electronic odometer, which displays the distance traveled on LCD displays, mileage readings are taken from a sensor that counts wheel revolutions.
Accordingly, the error in the odometer reading may not only depend on the natural errors of the device, but also directly depends on the condition of the tires and the serviceability of the vehicle’s chassis.
For example, if non-standard wheels and tires are installed on a car, the error in the odometer reading can either increase or decrease significantly. For example, on various auto forums there are many examples where car owners, by changing the standard wheels to a different size, not only reduced the error in the speedometer reading, but also reduced the error in the odometer reading.
What also affects the accuracy of the odometer readings
In fact, the accuracy of the mileage on the odometer depends on many factors. For example, even the height of the tire tread can affect the accuracy of the path traveled. The thing is that in modern cars, as we have already said, it is calculated by the number of wheel revolutions.
You understand that the height of the tire tread will determine the overall outer diameter of the wheel, which, naturally, will affect the number of wheel revolutions while driving on a certain section of the road. For example, the smaller the tire tread, the greater the number of full wheel revolutions will be recorded. And vice versa, the larger the tire tread, the lower the sensor will record the revolutions on a certain segment of the car’s path.
Odometer readings are also affected by tire pressure, as well as ambient temperature and even the duration of the journey. For example, if you are used to rarely checking the pressure in your wheels, and often drive on wheels that do not have enough pressure, then this leads to the fact that the wheels are heavily dented, which helps to reduce the outer diameter of the wheels.
As a result, the sensor that determines the number of full wheel revolutions when the tires are flat will count more wheel revolutions than at the normal pressure recommended by the automaker.
Even as we move, the pressure in the tires constantly changes. For example, due to changes in temperature outside. Also, during a long trip, the wheels heat up, which contributes to a change in tire pressure. As a result, all this greatly affects the odometer error.
How to check the speedometer and odometer errors in your car
There are many ways to calculate the speedometer and odometer errors in your car. However, again since these instruments are not accurate according to various technical standards, you cannot accurately calculate the error. But nevertheless, you can find out the average results. So how can we calculate how much the speedometer and odometer of your car are lying?
First, compare the speedometer readings with the navigation system readings. Remember this value. Then do the following:
Accelerate, for example, on the highway to 70 km/h and turn on, resetting the current fuel consumption and average speed data on the on-board computer. Next, after driving a little at the same speed on a cruise, look at the average speed on the computer, which is usually used to calculate the average fuel consumption in all cars for the last time.
There you will see far from 70 km/h, but a more truthful result, although also inaccurate. Although in most cases, as a result of such an experiment, you will see approximately the same speed as you saw when measuring speed using.
Now it's time to check how wrong your car's odometer is. There are several ways to accurately check the distance traveled. For example, a navigation system that can more accurately measure distances from point A to point B can also help you measure mileage on a certain route.
Therefore, before setting off, plot the route on your navigator. Next, note the mileage on the odometer and hit the road. At the end of the journey you will see the difference. Please note that in order to more accurately calculate the odometer error you need to drive as much as possible, since at short distances the error will be barely noticeable.
It is also advisable that your route be laid along a free highway, where you can accelerate to at least 100 km/h. The fact is that at lower speeds the error in both the odometer and speedometer will be small.
The second way to measure the distance traveled for comparison with the odometer reading is to drive along a highway with kilometer posts installed on it, which indicate a certain distance from any settlement from which the countdown is being made.
Your task is to choose a long route on such a highway with kilometer posts and drive along a certain section, checking the distance traveled with your odometer.
This will give you the approximate error of the odometer reading in your car.
Regardless of how exactly the speedometer shows speed, it is considered one of the most important devices in a modern car. We are forced to look at his testimony, otherwise we will not be able to avoid punishment for violating the speed limits in force in the country.
What is a speedometer/odometer combination?
The combined instrument indicates the driven speed in the car, measures the mileage traveled, shows the mileage of one trip and the instantaneous speed.
Attention! The speedometer scale helps the driver determine when to replace engine fluid and filters and calculate fuel consumption.
The speedometer is sometimes equipped with an odometer - a mechanism that measures the number of revolutions of the car's wheel. This way, the mileage traveled by the car is determined. It is possible to calculate daily and total mileage.
The odometer consists of:
- car revolution counter;
- an indicator showing the distance traveled in km or miles;
- speed recording device.
Odometers are classified into the following types.
- The mechanical device is considered the progenitor of modern devices. It was invented back in Ancient Greece.
Twisting such an odometer is as easy as shelling pears; all you have to do is act on the twisting mechanism. The mechanical odometer counter reacts to revolutions and converts them into kilometers. However, the disadvantage of such a device is that the data spontaneously resets when a certain value is reached. - The combined odometer is an improved model that makes it possible to correct data using a CAN rotary.
- A digital device operating on the basis of a microcontroller. Everything in such an odometer occurs digitally, and the readings of the device can only be influenced with the help of highly professional equipment. Electronic odometers are part of the car's on-board computer system.
The principle of operation of the speedometer is clearly visible in the example of a mechanical device. The speed change is carried out due to a mechanical connection between the gear shaft and the pointer. Both elements are connected by a cable of sufficient length, since the shaft is located far from the transmission. Its speed is determined by the finite amplitude of rotation of the wheels.
A special gear in the main gear rotates together with the output pulley and is also directly connected to a cable enclosed in a special protective casing.
Another required element is a disk-shaped magnet placed next to the steel drum. The latter is fixed to the needle, and the obtained indicators are displayed on a scale.
Even the electronic odometer has inaccuracies. They cannot be excluded, therefore it is customary to take into account certain standards that allow a limit to this value. For example, on a mechanical device the error should not exceed 5% -15%.
Device errors are explained by the presence of various gaps, weakness of the cable, poor grip and weak springs. A mechanical odometer produces more errors, a digital one produces much less, because it is possible to read the readings of a microcontroller and sensor.
There may also be an error on the speedometer, which calculates the speed of the car. The device is simply unable to display perfectly accurate information, since the speed depends on several components: rotation of the wheel, its diameter, etc.
It will be interesting to monitor the errors of the device at different speed modes.
- 60 km/h - there are almost no errors.
- 110 km/h - the error is 5-10 km/h.
- 200 km/h - the average value reaches 10%.
The error also varies according to the following points.
- On cars with front-wheel drive, the error appears at almost every turn. The reason is that the speedometer is integrated with one wheel. Because of this, turning to the left decreases the readings, turning to the right increases them.
- The error is affected by the non-standard wheel size. A difference of 1 cm increases the error to 2.5%.
- The diameter of the tire is important. At the slightest discrepancy with the standard, the speedometer readings are underestimated or overestimated.
- Tire pressure and tread wear can affect the error. For example, if the tire is poorly inflated, this leads to an underestimation of the maximum speed.
The most accurate readings are given, as mentioned, only by a digital device or a device connected to a GPS navigator. The benefits of satellite positioning cannot be underestimated. Modern systems demonstrate the exact speed of the vehicle without any errors.
The standard speedometer is marked with a scale of 10 km/h, and its needle twitches on potholes. He can only overestimate the readings, but not underestimate. Otherwise, the road situation will be falsely assessed and an emergency situation will arise. For example, if 100 km/h is displayed instead of the real 120 km/h.
A few words about errors associated with tire sizes. This is where the design of the speedometer itself comes into play. It consists of two devices combined in a single housing. One device measures speed, the other shows the vehicle's mileage. So they are called: high-speed and counting nodes.
Now specifically: if the car is shod with tires that are quite worn, the speedometer will overestimate the readings, since the gradation system comes into force every 10 km/h and the law of rounding numbers used in odometers.
Differences: speedometer and odometer
The odometer is mounted directly into the speedometer itself. For this reason, many people think that the device is a single device. Actually this is not the case:
- the speedometer only shows the speed of the vehicle;
- odometer - indicates the distance traveled in km.
The functionality of both devices is not interconnected, and the combination of both scales only affects the convenience of the driver.
Speedometer... Every motorist certainly knows about this device. However, not everyone can answer what an odometer is in a car, and this is quite natural, because this device is far from being as simple and primitive as it seems at first glance.
At the same time, not everyone sees the difference between an odometer and a speedometer - a completely different device combined with it. Well, we will try to clearly explain the differences, as well as what it is - a car odometer.
Operating principle of the odometer
In scientific terms, an odometer is a mechanical or electronic device that determines the number of revolutions made by a wheel, that is, a counter. Thanks to this information, the car owner can determine the path traveled by the car during its entire service life or over a certain period of time. That is, the information received by the device is communicated to the driver in numerical form, and specifically, the kilometers traveled.
The principle of operation of the device is as follows: for one kilometer traveled by a car, the wheel makes the same number of revolutions. Knowing how many revolutions it has made in total during a particular path, it is easy to calculate the kilometers traveled, and this is what is displayed on the odometer.
In addition, by resetting the odometer data before driving, you can easily set the distance from point A to point B or calculate how much the car traveled on one fuel fill. Probably any driver knows about all these functions of the odometer.
Their types
Despite the fact that the car is an invention of the relatively recent past, such a device as the odometer has been known for a very long time - its inventor was Heron of Alexandria. It is quite logical that the first mechanism of this kind was mechanical.
Actually, in the automotive industry, all odometers originally used were of a purely mechanical design, and the counter itself, located on the dashboard, was a set of drums with printed numbers that changed as the car traveled a certain distance (one kilometer or mile).
Such odometers were distinguished by their simplicity of design and reliability, but they also had several significant drawbacks. The main one was the limitation of the mechanical counter - when a certain mileage was reached, it was reset to zero.
In addition, the accuracy of such an odometer was achieved only when using wheels of a strictly defined size on a vehicle, and deviation from it caused a serious error in measurements.
In the mid-twentieth century, automakers began using electromechanical meters, which, receiving information from a mechanical sensor, displayed information not using archaic drums with numbers, but on a liquid crystal display.
Later, fully electronic odometers were created that received information about wheel speed from the so-called Hall sensor. At the same time, the information received from it was processed by the car’s on-board computer and stored in its memory, which made it possible to save information not only about the total mileage, but also about individual trips.
This was very convenient, for example, for measuring fuel consumption or distance traveled on several trips.
Odometer and speedometer: what's the difference?
As we have already said, not everyone knows about the difference between two completely different devices - the odometer and the speedometer. Many are misled by the fact that the odometer scale on almost all cars is integrated into the speedometer scale.
It is logical that some quite reasonably assume that this is the same device. In fact, the difference between the devices is very significant.
The speedometer is used to measure the speed of the vehicle and is in no way connected with the functions of the odometer - a counter for the mileage traveled by the vehicle.
The combination of the scales of these instruments is due only to the convenience of human perception of information, as well as tradition. However, today the odometer readings are displayed on the on-board computer display among the main information, and this display is again located in the area of the speedometer scale. However, these devices cannot be confused in any way.
Using the odometer to determine the mileage of a used car
It is well known that the odometer is the main means by which the mileage of a vehicle can be determined. This criterion is one of the most important, since the mileage traveled allows us to assess the general technical condition of the car, the degree of wear of components and assemblies, as well as the remaining engine life.
It goes without saying that many car enthusiasts who part with their own vehicle often have a desire to change the odometer readings in order to increase the initial cost of the car being sold.
We will leave aside the moral and ethical side of this issue and look at how technically realistic it is to “twist” the odometer counter.
Here we should once again delve into the history of this device. The first, mechanical, odometers had a serious drawback - it was very easy to change their readings. In fact, this reason forced automakers to look for various ways to protect data, which ultimately led to the creation of electronic devices.
In them, as we have already written, information about the total mileage is “hardwired” into the car’s on-board computer, and it is much more difficult to correct it. In practice, it is still possible to set the electronic odometer to negative, but this is done not by interfering with the operation of mechanical components, but by rewriting the information stored in it in the memory of the on-board computer.
Video about twisted runs on cars:
Today on the Internet there are many offers in this area, which is worth at least the well-known website odometr.rf, reviews of which speak about the relative simplicity of this procedure.
But do not forget that in most modern cars, information about mileage is stored in several electronic units independent of each other, and is quite capable of revealing the fact that the odometer readings are “twisted” on the part of the car enthusiast.
conclusions
As we can see, getting an answer to the question of what an odometer is is not so difficult. Knowing the operating principles of this motorist assistant, you can easily receive information about the distance traveled, find out the total mileage of the car, and control fuel consumption. Of course, this is one of the most significant devices in any vehicle.
Video - is it possible to find out if the mileage is incorrect (odometer readings) - tips for repurchasing.
