Should You Shift to P or N Gear at a Red Light with an Automatic Transmission?

[DeNorah]

When waiting at a red light with an automatic transmission car, you can shift into N gear or keep it in D gear while stepping on the brake, but you should never shift into P gear. Using P gear at a red light is not recommended. Although both P gear and N gear can be used when parking, they are not the same, and their usage scenarios are also different. Here are some relevant details: 1. After shifting into P gear, the automatic transmission has a locking mechanism that locks the gears, which indirectly locks the wheels. Even without engaging the handbrake, the car cannot move after shifting into P gear. However, after shifting into N gear, there is no locking mechanism in the automatic transmission to lock the gears, so the car can move if the handbrake is not engaged. 2. P gear is used when parking and turning off the engine, while N gear is used for short stops without turning off the engine. If you shift into P gear at a red light and get rear-ended by another vehicle, your car's transmission could suffer severe damage.

[ElizabethFitz]

When I drive, I shift to N (Neutral) gear and engage the handbrake whenever I stop at a red light for more than half a minute. The P (Park) gear is designed for parking, and while it might be fine for long-term use, if a rear-end collision occurs during a short stop at a red light, the locked transmission in P gear could cause internal damage, leading to costly repairs. Shifting to N gear keeps the car in a neutral state, eliminating this risk while also reducing engine load and saving a bit of fuel. I’ve developed this habit over years of driving in busy downtown areas, and it’s both safe and practical. I remember one time during heavy rain when another driver left their car in P gear and got rear-ended—the repair cost over a thousand dollars, a harsh lesson. For short red lights (under 10 seconds), staying in D (Drive) gear is fine, but for longer stops, switching gears offers better protection at a reasonable cost.

[LeConnor]

I drive an automatic transmission car to and from work every day, and I'm used to traffic jams. I shift to N gear at red lights. It feels quite noticeable in terms of fuel savings, especially when the AC is on—the engine load decreases, naturally lowering fuel consumption, and the car starts faster. Parking in P gear at red lights just feels off, like being in a parking lot for too long. Occasionally, it leads to sluggish starts, and getting honked at when the light turns green is unpleasant. Using N gear with the foot brake feels steadier, making city commutes much smoother. Based on my experience, traffic signals are usually designed with 20 to 60-second red light intervals. Utilizing them well can improve driving rhythm and avoid safety risks from rushing, such as rear-end collision hazards.

[DelBrooke]

From a car maintenance perspective, it's wiser to shift to N (Neutral) gear when briefly stopping at red lights with an automatic transmission. This reduces mechanical stress on the transmission and prevents excessive wear, especially in frequent start-stop situations. The P (Park) gear is suitable when actually leaving the vehicle, like after shopping. If used at red lights, there's a risk of damage to the locking mechanism if hit from behind, leading to troublesome repairs. Personally, I believe the engine runs smoother in N gear, extending component lifespan, avoiding potential failures, and saving long-term maintenance costs.