Yes, you can physically turn off a car that is in Drive (D), but you should never do it while the vehicle is moving, and it's a bad practice even when stopped. The correct procedure is to always shift the transmission into Park (P) before turning off the engine. Shutting off the car while in Drive can cause immediate mechanical stress and lead to long-term damage.
When you turn the key or press the start/stop button while in Drive, the engine stops, but the vehicle's transmission is still engaged to the wheels. If you are on any kind of slope, the car will immediately start to roll because Park is not engaged. The parking pawl—a small pin inside the transmission that locks the gears—only engages when you select Park. Forcing it to engage while the car is still moving even slightly can cause a loud clunk and potentially shear the pin, leading to a costly transmission repair.
Modern cars with electronic shifters often have built-in safeguards. Many will automatically shift to Park if the driver's door is opened while the car is stopped and in Drive, preventing a rollaway. However, relying on this instead of manually shifting is not a good habit.
Risks of Turning Off a Car in Drive:
| Risk Factor | Consequence | Likelihood |
|---|
| Vehicle Rollaway | Car rolls freely, causing an accident or injury. | High if on an incline |
| Transmission Damage | Stress or failure of the parking pawl mechanism. | Medium (cumulative damage) |
| Electrical System Issues | Improper shutdown sequence may cause error codes. | Low |
| Starter Motor Stress | Next start attempt may be harder on the system. | Low |
The only exception is in a genuine emergency, such as a runaway accelerator pedal. In that specific scenario, turning the ignition to the "Off" position (you may need to hold the button for a few seconds) is the correct action to stop the car. For all normal situations, the sequence is simple: come to a complete stop, press the brake, shift to Park, set the parking brake, and then turn off the engine.
