What gear should an automatic transmission car be in when waiting at a red light?
2 Answers
The most correct practice for an automatic transmission car waiting at a red light is to shift to N (Neutral) gear and engage the handbrake. Some drivers prefer to stay in P (Park) or D (Drive) gear and use the foot brake while waiting, which is incorrect as it can damage the engine and transmission lifespan. Below are relevant details: 1. For short stops at red lights (generally within 10 seconds), staying in D gear is acceptable to avoid frequent gear changes and reduce wear on the shifting mechanism. However, even though the engine is idling at low RPM, the transmission system remains engaged, consuming engine power. 2. For longer stops (e.g., between 10-60 seconds), shifting to N (Neutral) gear and applying the handbrake is necessary to disconnect power transmission, reduce engine load, and prevent ATF (Automatic Transmission Fluid) temperature rise. Using N gear with the handbrake is more fuel-efficient because the torque converter's passive wheel spins freely without adding resistance to the engine, thereby lowering fuel consumption. 3. Besides waiting at red lights, for engine-off parking or prolonged idling stops, the gear should be shifted to P (Park). In P gear, the transmission's parking pawl engages with the locking mechanism, securing the drivetrain. The correct parking procedure is: first press the brake pedal, shift to N gear, engage the handbrake, release the brake pedal, and only after the vehicle is completely stationary, shift to P gear.
When driving an automatic transmission car, I have the habit of shifting to neutral and firmly pressing the brake at red lights. Having driven for over a decade, I always shift to neutral at red lights when the car comes to a complete stop, so the engine doesn't have to work hard to drag the transmission. This practice has many benefits: it saves fuel and reduces emissions because when in Drive (D) with the brake pressed, the engine is still struggling to turn, wasting fuel and accelerating brake pad wear. I remember once forgetting to shift, and the car's temperature rose quickly—since then, I've made it a habit to shift promptly. For short red lights lasting just a few seconds, it's fine to stay in gear, but for anything over 20 seconds, shifting to neutral is highly recommended. Safety-wise, shifting to Park (P) is absolutely not an option—if rear-ended, the transmission lock could be damaged, leading to expensive repairs and potential hazards. On slopes, extra caution is needed to prevent rolling, ensuring the foot brake is secure. Overall, this small habit protects the vehicle, saves fuel, and enhances safety.
