Is an engine speed of 900 rpm normal?
2 Answers
An engine speed of 900 rpm is normal. Generally, the idle speed of an engine is around 750 rpm, and it increases to about 1500 rpm after starting. Hazards of excessive speed: Sudden acceleration to 5000 rpm may not necessarily damage the engine, but maintaining such high speeds for extended periods can significantly increase fuel consumption. Hazards of low speed: However, don't assume that low speeds are beneficial for the engine. For typical driving of family cars, the engine speed usually varies between 2500-3500 rpm, with idle speeds being lower, generally around 800-1500 rpm. If the engine speed is too low, fuel may not burn completely in the cylinders, leading to carbon buildup in the engine. Over time, this can cause more significant damage to the engine.
I remember driving my old Accord for over a decade, and it was quite common for the idle speed to hover around 900 RPM when parked, especially during cold starts or when the AC was on. An idle range of 700 to 1000 RPM is generally considered normal. With an older car, it might run a bit higher, but the key is stability—if the RPM doesn’t fluctuate and there are no unusual noises, it’s no big deal. Back when I was stuck in traffic on my way to work, the car would idle like that without any noticeable change in fuel consumption. If you’re concerned, just observe it after the engine warms up. If the idle speed drops back to 800 RPM once the temperature normalizes, everything’s fine. Don’t just focus on the numbers—what matters more is how the car feels when driving, as long as it’s smooth and steady.
