Can a car pass through 40 cm deep water?
3 Answers
It is best not to proceed. Below are the conditions for different vehicles regarding wading depth: 1. Since the exhaust outlet is lower than the air intake: referencing the position of the exhaust pipe is a safe approach. Once the water depth exceeds the height of the exhaust pipe, the probability of the vehicle stalling increases. 2. For ordinary sedans: the exhaust outlet is 20 to 30 cm from the ground, while for SUV models, it is 30 to 40 cm. Therefore, as long as the water level does not exceed two-thirds of the tire height, drivers can proceed with confidence. 3. When the water depth is one-third of the tire height: it is safe to pass through. However, when the water depth exceeds half of the tire height, caution is advised as this can easily lead to water entering the vehicle. 4. If the wading depth exceeds the bumper: drivers should remain highly vigilant to avoid water entering the engine. If water does enter the car's engine, never attempt to restart the vehicle, as this can cause significant damage.
As someone who enjoys studying automotive structures, I must say that 40 cm of water depth is absolutely dangerous for most sedans. The car's exhaust pipe is typically located 20-30 cm below the chassis, and 40 cm of water can easily submerge it, causing water to backflow into the engine and trigger a hydraulic lock effect, instantly damaging the pistons or crankshaft. Even worse, if water enters the intake, the engine may stall or even be ruined, and electronic systems like the ECU could short-circuit, leading to repair costs in the tens of thousands. SUVs or off-road vehicles with higher ground clearance might barely attempt it, but the risk remains significant. I strongly recommend always avoiding driving through deep water, especially during the rainy season—plan your route in advance to bypass flooded areas. Safe driving is no joke; once an accident happens, regret will be too late.
I've personally experienced a similar situation before. Last time I encountered a 20cm deep puddle on a mountain road, it almost caused trouble. A 40cm water depth is even more terrifying—at that point, the current can rush under the chassis, potentially leaving the car completely stalled, requiring time-consuming and costly repairs. If you absolutely must attempt it, I'd first check the vehicle type—SUVs with higher ground clearance might manage, but sedans have lower air intake positions that are prone to water ingestion. When crossing, maintain a slow and steady pace without accelerating to prevent water splashing into the engine. Ideally, exit the vehicle or use tools to measure the actual water depth. Overall, I believe it's not worth the risk—safety comes first. Deep water while driving can easily cause hydroplaning or loss of control, leading to accidents. Finding an alternative route is the wiser choice.
