Should You Shift to P or N at a Red Light with an Automatic Transmission?
4 Answers
When waiting at a red light with an automatic transmission, it is recommended to shift to N (Neutral) gear, and you can also engage the handbrake if the wait is longer. Briefly shifting to N gear at a red light is fine, but leaving it in N for an extended period can damage the car, especially the transmission. Reasons not to shift to P (Park) gear at a red light: 1. Shifting to P without engaging the handbrake can cause damage to certain components; 2. Starting from P gear involves cumbersome steps; 3. Frequently shifting to P can lead to gear grinding in the automatic transmission, damaging its bearings. The correct practice at a red light is: press the brake, shift to N gear, and when the light turns green, shift to D (Drive) gear to start driving.
I've been commuting by car for ten years, so I know a thing or two about waiting at traffic lights. Putting it in P gear? That's a big no-no! Last time, my colleague's car got rear-ended at an intersection because it was in P gear, and the transmission was completely wrecked. The repair cost was almost as much as a down payment on a new car. Now, if the red light lasts more than 30 seconds, I decisively shift to N gear and pull the handbrake. This way, the transmission gets to relax, and I don’t have to keep my foot on the brake. For shorter stops, I just stay in D gear and keep the brake pressed. Honestly, driving an automatic car requires some know-how—don’t take the easy way out by using P gear. The locking gear in the transmission can’t handle the stress, and if a rear-end collision happens, the insurance company won’t cover it. Since adopting this habit, my car runs much smoother.
Our auto repair shop receives vehicles with transmission issues every day, and many of these problems are caused by shifting into P gear at red lights. The P gear is designed for long-term parking, where the locking hook can jam the gears. If you're rear-ended at an intersection while in P gear, the impact force is entirely transmitted to the core components of the transmission. The safest practice is: for red lights under 30 seconds, simply stay in D gear and hold the brake; for longer stops, shift to N gear and engage the handbrake. Keeping an automatic transmission in D gear with the brake pressed for too long can cause the torque converter to overheat due to continuous stress. If your car has an auto start-stop function, it's even simpler—after the engine shuts off from braking, keep it in D gear without shifting, and it will automatically restart when you press the accelerator at the green light.
When I was a new driver, I also struggled with which gear to use at traffic lights. Later, I asked my driving instructor and learned that it's fine to stay in D gear and press the brake for short red lights, but shifting to N gear and pulling the handbrake is the most effortless if your foot gets tired. Now, whenever I see a countdown over 30 seconds, I immediately shift to N gear and pull the handbrake. Never use P gear! I once read on a car forum about someone who was rear-ended while waiting at a light in P gear, and the transmission repair cost over 8,000. Unlike manual transmissions with clutch protection, using the wrong gear in an automatic can trigger a chain reaction. Recently, I discovered another benefit of shifting to N gear at red lights: smoother starts without the jerking motion compared to starting from D gear.
