Do you know your car far and wide? Then say: what is it - an odometer? We are sure that only a small number of motorists will tell the correct answer. Therefore, it’s important for us to understand the features of this device. And also find out why they twist it, how it happens.
What is an odometer?
An odometer is a device that measures the number of kilometers traveled by a car. This is its fundamental difference from the more famous speedometer - the latter records the speed of movement of the vehicle.
Odometer readings are based on the calculation of the number of rotations of the wheel of the machine. Based on this, the device captures two types of measurements:
- Daily. This is the type of testimony that you can easily reset at any time by yourself by pressing the button. After that, the device will start counting mileage from scratch. This name was given to the measurement by taxi drivers due to the specifics of their work.
- The general. The mileage that the car has passed since it left the assembly line. These indicators, in theory, cannot be reset or reduced. However, many drivers still resort to such a procedure - how and why, we will analyze further.
The principle of operation of the device
Odometer - a mechanical or electronic device that determines the number of revolutions of a car’s wheel. These calculations help to know the length of the path that was traveled by the machine both from the beginning of operation and from a specific moment set by the driver. Information for convenience is displayed for the car owner in numerical form, expressed in kilometers.
How does the device work? For one kilometer the wheel makes a certain number of revolutions. By the sum of the latter, fixed by the device, it is possible to calculate how far the machine has traveled. So simple.
As we said, an odometer that measures mileage is not a speedometer that measures speed. Many drivers confuse these two different and independent devices, since often on the panel of a car their scales are actually combined.
Such an invention is far from a novelty. According to some reports, the mechanical odometer was invented by Heron of Alexandria.
Types of Odometers
We considered that it is an odometer. In a car, it can be represented in three varieties:
- Mechanical. The operation of such a device is simple. The mechanism includes a cable connected to the output shaft of the gearbox, as well as a counter equipped mainly with five reels. The rotation of the cable is transmitted to the last one. This starts the movement of the drums with printed numbers. The latter show the number of kilometers traveled.
- Electromechanical. Here, the rotation of the cable is not fixed by spinning drums, but by an electronic counter. The design is just as simple.
- Electronic odometer. Here the cable, as such, is absent altogether. Counts the distance traveled by a Hall sensor or electronic element. And the indicators are recorded on-board computer of the car. Today it is the most reliable and accurate type of odometer. However, it can also make measurement errors of up to 5%.
Invalid odometer reading
As we have already noted, there is a chance of displaying incorrect readings. Having learned that this is an odometer, you will want to understand how accurate this instrument is. Possible errors may be due to the following reasons:
- Wheel slip. They rotate, the odometer counts revolutions, and the car at this time stands still.
- Use of tires with a radius different from that on which the manufacturer’s odometer is “sharpened”.
- Intentional odometer correction by vehicle owner. How and why this is done, we will understand further.
Instrument Correction
Why do drivers twist readings on the device? The reasons for such actions for the most part are:
- Reduced real car mileage. This is done in order to sell a used car more expensive.
- The desire to hide the misuse of vehicles. For example, the operation of a company car for personal purposes at a time when, according to the documents, the car should be in the garage.
Do not think that only a professional can rewind the testimony. Today on sale you can find special equipment for these purposes, so almost everyone can handle it. But it is against the law. Some European countries face a prison sentence.
Consider in general terms how scammers work:
- Mechanical odometer. The easiest way to deal with it. The cable is removed from the shaft and attached to a drill or similar power tool, which helps to quickly rewind indicators to the desired. But not with all mechanical odometers, this trick does. Some need to be removed from the panel of the car for more complex manipulations.
- Electronic odometer. Special devices and software are already used here, the purpose of which is an on-board computer. How does this happen? The actions of the fraudster are aimed at reprogramming the controllers associated with magnetic sensors of motion and speed.
Now you know what an odometer is, how it works. Therefore, when buying a used car you need to be extremely careful - there is a chance that the readings of the device can be twisted by an unscrupulous seller.