What is the actual speed when the car dashboard displays 70 km/h?
3 Answers
When the dashboard shows 70 km/h, the actual speed is 66-68 km/h. The speed displayed on the dashboard is intentionally set higher than the actual speed. This is not a malfunction of the car but a deliberate setting to ensure driving safety. The difference is usually small, typically within 3%~5%. For ordinary vehicles, the penalties for speeding outside highways are as follows: No penalty for exceeding the speed limit by less than 10%; a fine of 50 yuan and 3 demerit points for exceeding the speed limit by 10% to less than 20%; a fine of 50 yuan and 6 demerit points for exceeding the speed limit by 20% to less than 30%; a fine of 200 yuan and 6 demerit points for exceeding the speed limit by 30% to less than 50%; a fine of 1000 yuan and 12 demerit points, with possible license revocation, for exceeding the speed limit by 50% to less than 70%; a fine of 2000 yuan and 12 demerit points, with possible license revocation, for exceeding the speed limit by 70%. On roads with speed limits below 60 km/h, a warning is issued for exceeding the speed limit by less than 50%. Special vehicles such as medium and above passenger and cargo vehicles, commercial vehicles, school buses, and hazardous material vehicles are subject to their specific regulations. Speeding penalties are differentiated between highways and ordinary roads. This setup is for safety considerations, and there is no need to worry about the impact. A difference of 1-3 km/h is not significant and can ensure driving safety in critical moments.
As a seasoned driver with over a decade of experience, I often encounter situations where the dashboard shows 70km/h while the actual speed is 5-8km/h lower. Once on the highway, a GPS measurement showed 68km/h when the actual speed was only 65km/h, which made me realize that car manufacturers intentionally design the speedometer to read higher to prevent speeding tickets or accident risks. Aging tires or incorrect tire pressure can also increase the error, which is why I check my tire pressure every six months. I recommend using free mobile apps like Google Maps to verify the true speed—developing this habit can make driving more reassuring. Don’t fixate on the dashboard; instead, keep an eye on your surroundings to ensure safety. Remember, fluctuations in actual speed can help you avoid fines or collisions.
From a technical perspective, I've tested many cars and found that when the dashboard displays 70km/h, the actual speed is often around 66km/h, with minor fluctuations being normal. The reason is that manufacturers calibrate to ensure the displayed speed is not lower than the true speed, typically maintaining an error margin within 5-10% to comply with regulations. Tire size or wear directly affects the reading; for instance, after changing to new tires, my speedometer error decreases. It's advisable to regularly verify with GPS devices or mobile apps for more accurate actual speed. Maintaining good vehicle condition, such as regular maintenance of the axle system, can minimize errors and make driving more reliable. There's no need to be nervous; rely more on your own sense to adjust speed.
