2009 BMW M3: Riding Out The Rain
January 20, 2010
As you might have noticed from a few previous posts, it's been raining a lot in Southern California this week. It's about as bad as Mother Nature gets around here ... if you ignore the occasional fires, floods, mudslides and earthquakes, that is. Yesterday was an interesting test of our BMW M3's wet-weather traction abilities. I was driving in heavy rain along the Tejon Pass, a hilly, 50-mile stretch of Interstate 5 colloquially called the Grapevine.
Having talked to some tire industry people over the years, I've come to learn that summer tires aren't inherently traction-deficient in wet conditions compared to all-season tires. In fact, in Inside Line's All-Season/Summer/Winter Tire Test, summer tires handily beat all-seasons in acceleration, braking and handling during wet conditions. The other nice thing about the M3 is its high level of communication with the driver -- if the tires are starting to lose traction because of water, you'll know about it.
The downside to our long-term car is that the tires are getting fairly worn (actually, three out of the four, since we recently replaced one due to a puncture). And this, according to Dan Edmunds, our in-house engineering/suspension guru, is a big determinant in how well a tire copes with standing water. Basically, the less tread depth there is, the less effective the tire becomes at evacuating and sequestering water.
Anyway, the M3 was generally fine yesterday. There were places that the M3 hydroplaned a little, but in general a reduced speed and some attentive driving were the only things required to keep the M3 safe. I was worried more about some other drivers (both of cars and big rigs) who didn't reduce their speed or respect the road the conditions. And judging by the variety of accidents I saw, I'd say some of them learned a harsh lesson.
Brent Romans, Senior Automotive Editor @ 15,374 miles