Peugeot Technical Operations Manager Ian Sedgwick said: “Although we’re all used to driving in the rain, deep water poses a new and unique set of challenges and some of our customers, quite rightly, aren’t sure how to deal with flooded stretches of road.”
Here are Ian’s answers to the most commonly asked questions.
How deep is dangerous for a car?
“It’s best to avoid flooded roads altogether. If you can’t and the water is more than 15cm deep – that’s about a third of the way up your wheel – don’t attempt it. If the water is up to the car’s sill, it could be deep enough to float it.”
How do I measure the water’s depth?
“Usually the crown of the road is the highest spot. If you can’t see the road markings look for familiar indicators such as the water line on kerb stones, a fence or wall.”
What if I’m not sure how deep the water is?
“If there are no vehicles already in the water and no indicators to enable an educated guess, don’t risk it. Flood water can rip up, carry and deposit all kinds of debris so you might be driving into a huge crater.”
How fast should I drive?
“Less is definitely more in safety terms. Enter the water at no more than 4 or 5mph. First gear tickover may be faster than this so you need to slip the clutch in order not to go too quickly. Keeping the engine revving prevents water entering via the exhaust pipe.”
Why so slow?
“You need to push the water aside, creating a depression in front of your car to prevent the engine sucking in water through its air intake. The faster you go the more the water is disturbed and the more likely it is to flood your engine.”
Are other cars a problem?
“The waves from other cars, particularly if they’re going too fast, will cause the water to become choppy and increase the risk of flooding to your car. If you can, wait for others to pass through and for the water to calm down.”
And once I’m through?
“Gently apply your brakes to remove excess water from the pads.”
What if the engine sounds strange afterwards?
“It might have swallowed some water. Driving a misfiring car could cause more damage. Stop immediately and seek expert advice.”
What if I breakdown out in the water?
“Put your hazard warning lights on and get out of the car. If that means letting water in, the upside is it could prevent the car from floating away. Lock the car and go for help.”
How can I prepare for driving in very wet conditions?
“Check your wiper blades. They should clear the screen efficiently and have a uniform wiping edge with no breaks in it. Make sure your battery is in good condition. If you have any doubts, your dealer can perform a simple test to check it. Finally examine your tyres. They should be in good condition, at the correct pressures, and with ample tread. The legal minimum for tread is 1.6mm but road safety experts recommend you change them at 3mm.”
Ian who has first-hand experience of what flood damage can do to an engine added: “By taking some sensible steps, drivers can limit the risk to personal safety and save themselves the possible expense of fixing a flood damaged car.”