What is the speed of a car at idle?
2 Answers
The speed of a car at idle is between 700 and 800 RPM, while the idle speed during a cold start typically ranges from 1300 to 1500 RPM. Engine wear is more severe when operating at low temperatures. To minimize wear, when the engine control unit detects a low engine temperature, it will increase the idle speed. This helps the engine reach its optimal operating temperature more quickly. Once the engine reaches the working temperature, the control unit will adjust the idle speed back to the normal range.
I noticed that when the car is idling, it mainly refers to the engine speed, not how fast the vehicle is moving. Normally, after the engine warms up, the idle speed is between 700 and 800 revolutions per minute (RPM). During a cold start, it might go up to 1200 RPM, but it drops back to normal once the engine heats up. For automatic transmission cars, when in Drive (D) or Reverse (R), the car will slightly creep at a speed of about 3 to 5 kilometers per hour, which is convenient for slow movement; for manual transmission cars in neutral, the speed is zero. An excessively high idle wastes fuel and increases pollution, while an excessively low idle can easily cause stalling. I once experienced unstable idling while driving in high-altitude areas, which nearly caused an accident, so regular maintenance of the throttle body and idle control system is crucial. Other factors affecting idle speed include the cleanliness of the intake system and whether the air-fuel ratio is correctly adjusted. In short, maintaining a stable idle is key—it ensures safe and fuel-efficient driving while avoiding unnecessary wear and tear.
