Here's how it happens, how to avoid it, and what to do when your car hydroplanes. Think of the grooves in your tires as miniature aqueducts. They pump water away from the contact patch where the rubber literally meets the road at an amazing rate. Tiremaker Continental estimates that, at 50 mph, the average new tire can disperse nearly eight gallons of water per second.
That's a lot to ask from a tiny piece of rubber operating on an area roughly the size of an adult man's outstretched hand. When a tire can't disperse water quickly enough, the contact patch starts to ride on the surface of the water, not the road—like water skis climbing onto the surface of a lake.
That's hydroplaning. Have you ever driven through a large puddle that was much deeper than you anticipated, only to feel the steering wheel go light in your hands? That sudden loss of feedback is how you experience hydroplaning. Many factors influence a tire's ability to resist hydroplaning.
The depth of its tread is the most important of them. The deeper those grooves are, the more water they can pump away from the contact patch. As the tire wears, the tread depth decreases—and your potential to hydroplane increases. It's easy to spot almost-bald tires: they're totally worn out when the tread grooves have faded almost entirely or if you notice the wear bars—strips of rubber crossing the width of the tire at 90 degrees to the grooves—are showing. They stand proud of the valley floor of the circumferential grooves.
To be sure of the tread depth, take a penny and place it in each of the circumferential grooves with the top of Lincoln's head pointed toward the tire.
If a groove doesn't overlap President Lincoln's head, your tires are at or below the legal minimum tread depth, increasing the likelihood of high-speed hydroplaning. You can also measure tread depth with a tread depth measuring gauge, as shown in the accompanying photo.
They're available at auto parts stores and at some tire dealers. Moreover, tires tend to wear unevenly, so check all of the grooves. If only one groove is under the legal minimum, it's best to replace the tire. Rotating your tires regularly ensures even wear. A tire with adequate tread depth will always resist hydroplaning better than one that's worn out.
The design of a tire's tread, called the tread pattern, is not an accurate visual indicator of its ability to resist hydroplaning. That's why Car and Driver has run instrumented tests on various types of tires in identical controlled conditions and on the same car to reach an accurate comparison. Tire Rack also does independent tire testing. Wet performance isn't a one-size-fits-all measurement, either. Much like driving on ice, the best reaction is to not overreact.
Safe recovery is more about finesse than brute strength. If you panic and brake hard or try to speed up, you risk making the skid or slide worse. If you feel your car changing direction on its own, let off the gas but don't hit the brake.
Then, although it may seem counter-intuitive, gently steer your car in the direction you are skidding. This is called "turning into the skid" and will help you regain control by realigning your tires with the direction your car is traveling.
Stay calm and wait for your tires to get their grip; stay alert for any other possible hydroplaning hazards ahead. Thankfully, most hydroplaning situations last only a few seconds.
Although it's important to know good techniques to deal with them, the best defense against hydroplaning is to make sure you have good tires and to maintain them properly. Check your tread depth and air pressure regularly and have them rotated every 3,, miles or during each oil change. Back to Knowledge Center. Environmental Tips.
Take our free sample driving test -- no registration required! Avoiding hydroplaning is not that hard if you know how it happens. There are several things that you can keep in mind while driving in the rain or on wet roads that will lower your chances of losing control of your car. Read the following tips and implement them the next time you drive on a wet roadway:. Most automobile safety experts agree that hydroplaning is most likely to occur at speeds greater than thirty-five miles per hour.
As soon as the first drops hit your windshield, slow your speed considerably. It is best to drive five to ten miles slower than the speed limit, even slower in heavy rain or windy conditions. Sudden increases in speed, such as those required to pass, put you at a greater danger of hydroplaning. Avoid sudden accelerations at all costs. Keeping your tires in tune will also help prevent your car from hydroplaning on wet roads. This is particularly important for drivers who live in areas of the country with frequent rainfall.
Replace your tires regularly. Driving on slick or bald tires can be detrimental on wet roadways. If you were to begin hydroplaning while driving with the cruise control on, it will take additional time for you to disable the function before beginning to regain control of your vehicle.
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