When it comes to engines, achieving the desired low idle speed is crucial for optimal performance. There are several synonyms that can be used to describe this ideal idle speed, including "optimal idling RPM," "desired idle RPM," "target idle speed," and "ideal resting RPM." Each of these phrases refers to the desired engine speed while the vehicle is in neutral and not accelerating, typically ranging between 600 and 900 RPM. It's important to maintain this speed to ensure a smooth engine performance and conserve fuel. Whether you call it the "optimal idling RPM" or the "ideal resting RPM," keeping your engine's idle speed at the desired level is vital for a healthy vehicle.