What is the normal idle speed for a car?

[DeDamian]

Car idle speed is normally maintained between 600 and 900 RPM. Currently, there are two types of engines on the market: turbocharged and naturally aspirated. Due to differences in engines, idle speed values vary. Even for the same engine model, idle speed values may differ because of different tuning. Idle speed is a working condition of a car, referring to the engine running in neutral gear. The engine speed at idle is called the idle speed, which can be adjusted by changing the throttle size, among other methods. If the idle speed fluctuates significantly during adjustment, it can cause early wear to the engine. It is recommended to have it adjusted at an automotive repair service.

[LeLandon]

Generally, a car's normal idle speed ranges between 600 to 900 RPM, but it depends on the vehicle model and driving habits. I've driven Volkswagen cars where the idle stabilizes around 750 RPM after warming up, running very smoothly. When starting cold, the idle speed might be higher, possibly reaching 1000 RPM, but it drops down within a minute or two. If the idle speed is consistently too high, say over 1000 RPM, it could indicate a dirty throttle body or carbon buildup issues, which can increase fuel consumption and accelerate engine wear. If the idle is too low or shaky, it's crucial to check the spark plugs or fuel injection system immediately to avoid major issues. Remember, new and old cars differ; vehicles over 10 years old are more prone to idle fluctuations, so regular cleaning of fuel injectors and similar maintenance is recommended.

[Avery]

I often help friends with car repairs. The normal idle speed range is 600 to 900 RPM, depending on the engine type. Gasoline engines usually idle around 700 RPM, while diesel engines may be slightly higher at 800 RPM. Based on practical experience, unstable idle speed is mostly caused by intake system issues, such as a clogged air filter or faulty sensor, leading to fluctuating RPM. A temporarily high idle speed after startup is a normal protective mechanism, but persistently high idle requires checking spark plugs or electrical circuits. Don't ignore abnormal idle speed—small issues can escalate into major repairs. Different car brands also vary; Japanese cars have stable idle speeds, while German cars are more sensitive. If idle speed is abnormal, it's more reliable to get a professional diagnosis.

[LeGraham]

As an average driver, it's sufficient to know that normal idle speed is around 700 RPM – too high wastes fuel, too low causes stalling. Cold starts may show higher idle, but it should settle between 600-800 RPM when warmed up. If you notice unstable RPM or unusual noises, pull over immediately for inspection. Idle issues often stem from weak batteries or aged ignition coils. Novices should avoid tampering with ECU settings. Remember, lower idle saves fuel and reduces noise.

[McDiana]

I've been driving for over 20 years. An idle speed between 650-850 RPM is considered standard, with significant variations depending on the season. In winter when temperatures are low, the idle speed may surge above 1000 RPM during warm-up, then normalize after a few minutes. In summer, it's more reasonable to have slightly higher idle speed when the AC is on. Common causes of unstable idle include fuel system blockages or ECU malfunctions, which affect emissions and environmental protection. It's recommended to check idle conditions during each maintenance service to prevent sudden stalling accidents. Modern vehicles with auto start-stop systems can reduce idle energy consumption.