What is the correct way for a car to pass through deep water?
2 Answers
When driving through deep water, the depth of the water should be assessed. Upon entering a waterlogged road, it can be difficult to judge the depth due to the murky water, especially on uneven surfaces. The safest approach is to first park the car in a safe location and observe how other vehicles navigate the flooded area. If vehicles of similar height can pass safely, it generally indicates that your car can also pass. If there are no similar vehicles to reference, it's advisable to use a stick to measure the water depth. The safe and dangerous water levels, as well as the maximum water depth your car can handle, are typically specified in the vehicle's manual. When the water reaches half the height of the wheels, the car's chassis may already be submerged, and the exhaust pipe might be in contact with the water. For components with poor sealing, water may seep in, requiring reapplication of lubricant or rust removal for some parts. For most passenger cars, water up to one-third of the wheel height is generally safe. When the water reaches two-thirds of the wheel height, the battery may be at risk of water ingress. If the car is driven too fast, water could enter the air intake, potentially causing severe engine damage. Important considerations when driving through water: For vehicles with auto start-stop systems, manually disable this feature before entering water. If the engine stalls in water, the auto start-stop system might attempt to restart the engine, which could lead to major repairs. Drive slowly through water and shift to a lower gear after entering. Avoid stopping midway, maintain a slow speed, gently press the accelerator, avoid sudden steering, and do not change gears. Never attempt to restart the engine if it stalls due to water ingress, as this could destroy the engine. In such cases, exit the vehicle and wait for assistance. Avoid driving side by side with other vehicles when passing through flooded areas. Maintain a safe distance and pass through one at a time to prevent water splashed by other vehicles from entering your car's air intake. After passing through the water, perform several light brake applications to generate friction between the brake pads and discs, helping to evaporate any water on them.
I've been driving for over 20 years, and every time I encounter a waterlogged road section, I always stop first to estimate how deep the water is. Never just charge straight in. Ideally, the water depth shouldn't exceed half the tire height or the exhaust pipe level. If it's too high and you force your way through, water can enter the engine through the air intake, leading to costly and troublesome repairs. If you can't clearly see the water level, get out and use a stick to test it or wait to see how others navigate it. When you decide to proceed, shift into first gear or a low gear, maintaining a steady and slow speed—don't exceed 10 km/h. Going faster will splash water, impairing visibility and potentially wetting electrical wiring. After crossing, don't forget to check your brakes. Their sensitivity decreases when wet, so lightly press the brakes a few times to ensure they're working properly. Always keep a small flashlight in your car to easily check if there's water in the exhaust pipe. Remember, safety is more important than rushing. If in doubt, take a detour—don't take unnecessary risks.
