What is the normal idle speed for a sedan?
3 Answers
Car idle speed is generally between 700-800 RPM. The specific details about idle speed are as follows: Definition: Idle speed refers to an operating condition of a car. When the engine runs without load, it is called idling, meaning the car is in neutral gear. The engine speed during idling is called idle speed. Idle speed can be adjusted by modifying the throttle opening size. Idling means the engine is running but not delivering power. Normal Idle Speed: When the vehicle is parked and the engine is started, the minimum stable operating speed of the engine is called parking idle speed (the process of the engine transitioning from cold idle speed to normal operating temperature idle speed is called warm-up or heating).
I've been driving for twenty years, and the ideal idle speed for a sedan is usually around 700 RPM. If it's too high, like above 800 RPM, the engine noise increases and fuel consumption spikes; if it's too low, like below 600 RPM, the car is prone to stalling at intersections or having difficulty starting. I remember once my old car had unstable idle speed, and after inspection, it turned out to be carbon buildup in the throttle body—cleaning it fixed the issue. Normally, I warm up the car for about a minute until the idle speed drops from over 1000 RPM to a steady 700 RPM. In summer, when the air conditioning is on, the idle speed might rise to 800 RPM but quickly adjusts back. Long-term abnormal idle speed can damage the engine and increase fuel consumption, so I recommend checking the idle speed gauge every six months or getting it tested at a professional shop. A healthy idle speed ensures the car runs farther and safer.
As a car enthusiast, I often help people with idle speed issues. The normal range is generally between 650 to 850 RPM depending on the vehicle model. Older naturally aspirated cars tend to have lower idle speeds, while newer turbocharged models may run slightly higher. If idle speed drops below 600 RPM, the engine may stall; if it exceeds 900 RPM, it wastes fuel and may cause knocking. A healthy idle should show steady needle movement without fluctuations - any instability might indicate oxygen sensor issues or a clogged air filter. Cold starts typically run around 1000 RPM before settling down after warming up. I recommend checking your vehicle's manual as specifications vary by brand - Japanese cars often have lower idle settings while German models run slightly higher. Proper idle speed management improves fuel economy and prevents minor issues from developing into major problems.
