What is the normal engine speed for a sedan?
2 Answers
Normal sedan engine speed is around 2200 to 2500 RPM. Regardless of the gear, maintaining the engine speed at approximately 2200 to 2500 RPM is the most fuel-efficient. The engine speed is related to the number of work cycles per unit time or the effective power output of the engine, meaning the effective power varies with different speeds. Therefore, when specifying the effective power of an engine, the corresponding speed must also be indicated. The effective power and its corresponding speed specified on the engine nameplate are referred to as the rated power and rated speed, respectively. The operating condition of the engine at rated power and rated speed is called the rated condition. Rated power is not the maximum power the engine can produce; it is the maximum usable limit of effective power determined based on the engine's intended use. For the same engine model, the rated power value may differ depending on its application, and the effective torque also varies with the engine's operating conditions.
In my daily driving experience, the engine RPM of a normal car varies quite a bit. At idle, it's usually around 800 to 1000 RPM, like the value shown on the dashboard when the car is stopped at a red light. When cruising on flat roads, maintaining a stable RPM between 1500 and 2500 is the most economical. If accelerating to overtake or going uphill, the RPM can rise to 4000 or even higher, but don't let it rev too aggressively for too long, as this can significantly increase fuel consumption and wear out internal engine components. I've driven several different car models, and with smaller or older cars, the idle RPM can sometimes be higher, like around 1100 RPM during a cold start in winter, but it drops back to normal after a few seconds. Overall, the tachometer is right in front of the steering wheel—just glance at it occasionally to ensure the RPM is in the green safe zone. Driving gently and keeping the RPM steady between 1500 and 2500 can extend engine life and save on fuel costs.
