At what water level does a submerged vehicle become dangerous?

[ODakota]

When a vehicle is submerged above the tire level, it becomes dangerous. Reasons for the danger: The biggest concern when a vehicle is submerged in water is the impact on the engine and electrical systems. If water enters the engine intake, it can directly affect the engine. Safe water level: Generally, water levels below the intake are considered safe. However, the height of the engine intake varies across different vehicle models, as does the level of electrification and the lowest electrical component positions. High failure rate of water-damaged vehicles: Automobiles contain a large number of electronic components. If submerged, the reliability of the vehicle in the future can be compromised. Even after replacements, it is difficult to guarantee the vehicle's reliability, and the likelihood of failures increases over time. Water-damaged vehicles develop odors: When the interior is submerged, odor is an inevitable issue. Since the usual treatment methods include rinsing, drying, and sun exposure, some hidden areas can easily become breeding grounds for bacteria, leading to unpleasant odors.

[LeRuby]

Last year, I encountered heavy rain while driving, and my car was submerged to half the height of the wheels, resulting in circuit damage that cost over ten thousand yuan to repair. When the water level reaches about half the wheel height (around 20 cm), it becomes dangerous as it may trigger ABS and brake failure. If it rises further to the bottom of the doors (around 40 cm), water can enter the exhaust pipe, causing the engine to stall, and the car may even float and lose control. Beyond 60 cm, the entire car can float or be submerged, making it impossible to open the doors. During heavy rain, I avoid driving if possible. If trapped in water, immediately unbuckle the seatbelt and escape through the doors—safety comes first. Even seemingly shallow flood levels pose hidden risks, as underwater pits or debris can be hazardous, and high-speed water wading is harder to control. Post-flood handling is troublesome, with rapid depreciation and reduced resale value. It's best to regularly check window seals and drainage holes as a preventive measure.

[DelCollin]

As someone who loves studying cars, I've found that the critical factor in flooding situations is the vehicle's ground clearance. Water levels below 15 cm are generally fine, but exceeding 20 cm starts causing issues—like water ingress leading to blown fuses or electrical shorts. Between 25 cm and 30 cm, water reaches the air intake, and the engine gets ruined the moment it sucks in water. At 40 cm or higher, the car might float away and crash into walls, which is extremely deadly. My advice is not to rely on gut feelings when assessing rainwater levels; it's better to use a stick to measure the water depth before deciding, or simply take a detour via higher ground. Post-flooding, rust and corrosion become long-term risks, requiring replacement of all undercarriage components—repair costs could buy you a used car. When dealing with flood-damaged vehicles, immediately disconnect the battery to prevent spontaneous combustion—safety comes first.

[BradleyFitz]

When taking my child out, my biggest concern is the car getting flooded. If the water level rises 15 cm above the ankles, there's a hidden danger as it's easy to trip or slip. Once it reaches 20 cm at the wheel hubs, the car starts shaking and water begins to seep in. The more dangerous threshold is at 30 cm, where water pours in through the door gaps and floods the seats, trapping and terrifying the child inside. The safest option is to stay home during heavy rain. If driving is unavoidable, steer clear of low-lying areas and evacuate with the child if the water level rises slightly. Flooding not only damages the car but also poses personal danger, and the high cost of towing and repairs makes prevention the better choice. Installing a high-position intake hose on the car can help a bit.