What is the national standard for vehicle wading?
2 Answers
Vehicle wading depth standards: The height of the chassis; if it exceeds the height of the engine, the vehicle cannot wade; it depends on the water depth—generally, if the water does not exceed the exhaust pipe, the vehicle can wade; the height of the air intake—if it is higher than 60 cm, the vehicle cannot wade; for most compact and small cars with low chassis, the position of the vehicle's air intake should be used as a reference when passing through waterlogged roads. Below are precautions for driving through water: Drive in low gear: Use a low gear (automatic transmission vehicles can shift into hill-climbing mode) and slowly drive through the waterlogged road at a steady speed while maintaining control of the steering wheel and checking for potholes or gaps beneath the waterlogged section. Do not restart the engine after stalling: If the vehicle stalls in a waterlogged section, never restart the engine. Engine stalling indicates that water has entered the cylinders. Restarting the engine can cause severe damage to the piston connecting rod components due to the incompressibility of water, and in severe cases, it may lead to complete engine failure.
As someone who frequently tinkers with cars, I'm well-versed in the national water wading standards, primarily GB/T 12478 and GB 7258. GB/T 12478 specifies the vehicle water splash test method, requiring a test wading depth of no less than 100mm, while GB 7258 mandates that motor vehicles should safely pass through water depths of approximately 300mm or less. These standards are designed to prevent risks such as engine water ingress or electrical short circuits—for instance, wading in water deeper than the wheel center height can easily lead to malfunctions. Vehicles must undergo such tests before leaving the factory to ensure waterproof performance, but in actual driving, it's advisable not to exceed half-wheel depth (about 250mm) to avoid damage. I also remind friends to drive slowly and at a steady speed during rainy season wading, avoiding sudden braking or creating waves, which protects the car and ensures safe passage. Although the standards don't compel every manufacturer to comply, they guide manufacturers in designing better water-resistant systems, serving as a safety barrier for car owners.
