What gear should an automatic transmission use when crossing water?

[LaHarley]

When driving an automatic transmission vehicle through water, the correct method is to engage the L gear or manually select the 1st gear in a manual-automatic transmission. While crossing, lightly press the accelerator to maintain the engine speed around 2000 RPM. Below is an introduction to the automatic transmission gears: 1. P (Park): The parking lock position. When the gear lever is moved to this position, the drive wheels are mechanically locked. The gear lever can only be moved to this position when the vehicle is completely stopped. To move the gear lever out of this position, the brake pedal must be pressed, and the ignition switch must be turned on. 2. R (Reverse): The reverse position. Move the gear lever to this position when reversing. The gear lever can only be moved to this position when the vehicle is completely stopped. 3. N (Neutral): The neutral position. When the gear lever is moved to this position, the transmission does not engage any gear. No power is transmitted to the wheels in this position, and the engine braking function cannot be utilized. 4. D (Drive): The driving position (normal shifting program). When the gear lever is moved to this position, the transmission automatically shifts up and down within the engine speed range. The shift points depend on engine load, the driver's driving style, and vehicle speed. 5. S (Sport): The driving position (sport shifting program). When the gear lever is moved to this position, the transmission automatically shifts up and down within a higher engine speed range compared to D gear, making full use of the engine's power. The shift points depend on engine load, the driver's driving style, and vehicle speed.

[Francisco]

When driving through flooded areas, I switch to the low gear of the automatic transmission, such as L gear or 1st gear in manual mode. This slows down the vehicle and increases torque, ensuring stable progress without skidding or stalling. If the water level is too high, it can enter the exhaust pipe, causing engine failure or even major repairs, so avoid water deeper than half the wheel height. I usually turn off the air conditioning fan to reduce the risk of water intake and maintain a steady throttle without shifting gears. After passing through, check the engine sound and undercarriage for any water ingress. If the engine stalls, do not attempt to restart it forcefully—call for a tow truck instead. Safe driving prioritizes stability, so avoid risky deep-water crossings and be prepared to take detours when necessary.

[HannahFitz]

Anyone who knows a bit about cars understands that using a low gear when crossing water protects mechanical components. I shifted to L gear, and the transmission locked well with stable hydraulic pressure, reducing the risk of water impact damaging the internals. The engine maintained high RPM at low speed to prevent exhaust pipe backpressure from sucking in water, which could lead to engine failure. During the process, avoid letting water submerge the air filter. Afterward, check the transmission fluid and battery connections for any water ingress. This approach helps prevent short circuits or mechanical failures, extending the vehicle's lifespan and saving on repair costs. Remember, water depth should not exceed the height of the foot brake—proceed slowly and safely.

[SanAbel]

When I first started driving, my instructor taught me to use a slow gear for water. In an automatic transmission, shift to L or 1st gear, and the car will move steadily like a turtle crawling, without suddenly stalling and stopping. Just make sure the water depth doesn't exceed the center of the wheels. Keep your foot lightly on the accelerator while driving, neither accelerating nor braking to avoid skidding. After passing through, just glance at the engine to make sure it's normal. For beginners, this method is simple, worry-free, and safer—just practice slowly and you'll get used to it.

[HavenAnn]

Having driven automatic transmission cars for over a decade, I've developed tricks for frequent water crossings. Switching to L gear to lock in first gear is most practical—maintain a steady speed around 2000 RPM without shifting, ensuring water depth doesn't exceed half the tire height. Once, I forgot to use low gear, stalled, and paid for a tow truck—a costly lesson. Now, I always use low gear at moderate speed, turning off the fan to reduce risks. After crossing, let the car idle for minutes to dry out, checking for abnormalities. Experience taught me to scout the route early for safe, hassle-free water crossings.