Will an Automatic Transmission Car Move Without Pressing the Accelerator?
3 Answers
Whether an automatic transmission car will move without pressing the accelerator depends on the gear position: 1. If the gear is in P (Park) or N (Neutral), the car will not move whether you press the accelerator or not; 2. If the gear is in any position other than P or N, the car will move even without pressing the accelerator. For an automatic car in D (Drive) gear without pressing the accelerator, it is equivalent to a manual transmission car in 1st gear without pressing the clutch—this is the starting gear, and the car moves very slowly. For manual transmission models, this function is achieved through the clutch. When starting the car, if the accelerator and clutch are properly coordinated, the car will slowly move forward, also known as "creeping." If the clutch is released too quickly, the car will not only fail to move but may also stall.
When I previously drove an automatic transmission car, I noticed that the car would indeed move forward slowly without stepping on the accelerator when starting. This is called the idle crawl function, because the engine pushes the vehicle at low idle speed when in D gear. It is very practical on flat roads or in urban traffic jams, allowing for easy following without constantly pressing the accelerator, reducing fatigue. However, on steep slopes, the idle power may be insufficient, and the car might roll back or not move, in which case you must step on the accelerator for assistance. When I first started driving, I encountered this problem on a slope and got a scare. Later, I developed the habit of lightly pressing the accelerator when starting on slopes. For safety, new drivers can practice on flat sections to familiarize themselves with their car's idle speed, which is generally safe at 2-5 kilometers per hour. If it's too slow or abnormal, it might indicate engine or transmission issues, and timely maintenance can prevent trouble.
Automatic transmissions typically allow the vehicle to creep forward without pressing the accelerator, based on engine idle torque and torque converter principles. As someone who frequently studies automotive systems, I know that at idle, the engine runs at low RPM but still transmits minimal power to the wheels, causing this creeping motion. In daily driving scenarios like parking lots or traffic jams, this design enables smoother starts. However, on slippery surfaces or steep inclines, idle stability may be compromised – I've observed reduced creeping force during rain/snow, requiring throttle input for added propulsion. Regular checks of engine oil and transmission fluid levels are recommended to maintain system health. If idle creeping becomes excessively slow or disappears, it could indicate electrical issues or transmission wear; professional diagnosis is advised to prevent accidents.
