Adam's got a nasty tendency towards hydroplaning. What can he do to put a stop to all the sliding? Find out.

Dear Car Talk

Dear Car Talk | May 01, 2007

Dear Tom and Ray:

I have a history of hydroplaning. I slid and rolled over in a GMC Jimmy while making a sharp right turn during a rainstorm. I also have hydroplaned in a Jeep Cherokee while driving in a light drizzle and going in a perfectly straight line. I now own a Honda Civic. As I will obviously be driving in the rain once more, what is the best strategy for not letting it slide around? I had thought that not turning too fast would be a grand solution, until the Jeep incident. Any thoughts on the matter? Thanks! -- Adam

RAY: Yeah. Slow down.

TOM: It's hard to know what happened in each situation, Adam. But there are several factors that often lead to hydroplaning.

RAY: The first one is speed. If you're going too fast and you hit standing water, the vehicle is going to hydroplane (that is, the tires will not be able to channel enough water out through their grooves, and the tires will ride up on top of the water, losing their contact with the road).

TOM: So if you drive like a knucklehead in the rain, whether you're going straight ahead or not, you're a candidate for hydroplaning.

RAY: Tires also can be an issue. Knobby, aggressive SUV tires are notoriously bad on wet pavement. It has to do with both the nature of the rubber compound used and the fact that they have deep grooves and, therefore, a smaller rubber patch on the road to begin with. So they tend to slide fairly easily. And while the deep grooves can help evacuate water, if you're going too fast, that's not enough.

TOM: Another factor is the size of the puddle you hit. If you live where there's flash flooding and standing water builds up on the roads, you have to be extra careful. If you drive into 2 or 3 inches of water, even at what normally is a reasonable speed, you easily can hydroplane.

RAY: And finally, your four-wheel-drive system could have been a factor. The GMC Jimmy and the Jeep Cherokee both have old-style "on-demand" four-wheel-drive systems (as opposed to modern, full-time all-wheel-drive systems). Those old-style systems are never supposed to be used when driving on normal roads -- dry or wet -- because they force the two front wheels to turn at the same combined speed as the pair of rear wheels.

TOM: If you try to steer a vehicle without letting each of its wheels turn at different speeds, you easily can lose control and flip it over. Or you could make it hard to regain control once you start to hydroplane.

RAY: Those old-style four-wheel-drive systems are supposed to be engaged only when you're stuck, or when you're actually driving on mud, sand or snow.

TOM: So make sure you have good tires on your Civic, watch out for large puddles and slow down, Adam. That should keep you on terra firma. Did we mention that you should slow down?

Get the Car Talk Newsletter

Got a question about your car?

Ask Someone Who Owns One