Why Does the Car Odometer Automatically Decrease?
2 Answers
The mileage of a car does not decrease automatically. It is possible that the trip mileage was pressed, in which case the mileage usually removes the ten-thousands digit directly. For example, if it originally displayed thirteen thousand miles, pressing the trip mileage might change it to three thousand miles. Definition of Mileage: The car's mileage starts counting from zero when it leaves the factory, and there are at least two mileage counts. One of them is the total mileage, which is the total distance from the factory to the present. It will always increase and never decrease, regardless of the environment. The other is the trip mileage, which can be reset midway. Many car owners also use the trip mileage to calculate how far a full tank of fuel can go. Precautions: Different fuel grades will have different fuel consumption performances. Generally speaking, vehicles that use 95-octane gasoline will have better fuel consumption performance if 98-octane gasoline is used. This is because higher octane ratings can provide better engine performance. If you find that your fuel consumption was originally eight liters per hundred kilometers and now it has become seven liters, it may be due to the use of higher-octane gasoline.
I remember a few years ago, when I was driving an old Toyota, the odometer suddenly started rolling backward. That experience made me realize it could be due to worn mechanical parts—like gear slippage or a damaged spring, which is common in older cars, especially after driving on bumpy roads. Or, someone might have tampered with it intentionally, like adjusting the odometer to hide high mileage and boost the resale value, which is both illegal and risky. However, in modern cars, the electronic systems are more complex, and issues like sensor failures or software glitches can also cause a reset—for example, if the battery suddenly disconnects, the computer readings can go haywire. Whatever the reason, I’d recommend getting it checked at a professional repair shop immediately; an inaccurate odometer not only affects resale value but could also mask maintenance problems, leading to unaddressed brake or engine issues and increasing accident risks. Personally, I always keep service records as proof after such incidents, putting safety first.
