Does the automatic transmission move by itself in D gear?
3 Answers
Whether an automatic transmission vehicle moves by itself in D gear depends on the design and tuning of different vehicles. Type of transmission device: Whether an automatic transmission vehicle moves by itself in D gear is related to the type of power coupling device in the transmission. For example, continuously variable transmissions use multi-plate clutches. When the user shifts into D gear, the clutch remains disengaged, and no power is transmitted, meaning the vehicle stays stationary. When the user presses the accelerator, the clutch gradually engages, allowing power to be transmitted, and the vehicle starts moving. Other factors: The amount of power output in idle D gear, i.e., whether the vehicle moves by itself after releasing the brake, depends on the design of the torque converter, the control of oil pressure, and the engine speed.
When I first drove an automatic transmission car, I was genuinely curious whether the car would move on its own in D gear. To my surprise, after releasing the brake, the car indeed crept forward slowly, like a tortoise crawling. This is a well-designed feature to make starting smoother, especially when waiting at traffic lights or on slight inclines, preventing rollback without needing to press the accelerator. However, please note, this is not autonomous driving; you still need to press the accelerator to speed up, otherwise, the car will move at a very slow pace of about 5-10 km/h. Initially, this made me a bit nervous—I accidentally let the car creep a tad too far in a parking lot, but thankfully, no collision occurred. This creeping phenomenon stems from the torque converter transmitting a small amount of power to the wheels at idle, making it easier for beginners to operate. After driving for so long, I've grown accustomed to relying on it to save some effort in traffic jams, but safety always comes first.
Having driven automatic transmission cars for twenty years, we jokingly refer to the creeping characteristic of the D gear as 'an old ox pulling a cart'—it slowly crawls forward when you release the brake, without suddenly darting off. This creeping design makes the starting process as natural as breathing, especially when starting on a slope without any stress. Looking back to the days of driving manual transmission cars, where you had to master the clutch, now all you need to do is control the accelerator and brake. However, it's important to remind that the illusion of the car moving on its own can be quite dangerous in tight spaces; once, a friend mistakenly thought the car was fully stopped, released the brake, and lightly scraped the guardrail, costing hundreds to repair. Remember, the creeping function only provides auxiliary power, so avoid getting distracted by your phone in crowded areas. Developing the habit of checking your surroundings before starting can save a lot of trouble.
