With the next round of winter rains ready to sweep through the South Bay next week, it’s important not to take safe practices – specially while driving cars – for granted. And while we’ve seen some major storms drop nearly four inches of rain in the area, driving in even a light rain can be nearly as dangerous, here’s why:
Under all condition, but especially in the rain, your car’s tires are the only contact between you and the road. All acceleration, steering and braking goes through the tires. On dry roads changes in the performance of your tires is barely perceptible, but on wet roads it can be significant. For example tires that are only half worn (not down to the 2/32” wear bars but with as much as 7/32” or 8/32” of remaining tread depth) have significantly reduced wet weather performance, according to tests conducted by Consumer Reports.
According to Consumer Reports while hydroplaning can start at 36 mph for a half-worn tire versus 40 mph for a new tire, what’s more startling is the lose of braking traction. The Consumer Reports tests showed that a half-worn tire stopped from 3 to 6 feet longer at just 40 mph versus a new tire. That’s nearly half a car length and a certain rear-ender in tight traffic.
But even fairly new tires can have reduced wet weather performance if they’re not properly inflated. According to the National Transportation Safety Board (NHTSA) a new tire that’s inflated to 36 psi will hydroplane at 62 mph while the same tire with a reduced inflation pressure of 25 psi will hydroplane at just 52 mph.
How prevalent are under-inflated tires? According to Dan Zielinski of the Rubber Manufacturers Association a survey conducted in Sacramento in 2009 found that only 9% of the 465 vehicles inspected had all four tire properly inflated and a full 49% (half!) of all vehicles inspected had at least one under-inflated tire.
Even for professionals it’s difficult to visual spot an under-inflated tire. A tire can be as much as 30% under-inflated and still appear to be properly inflated, according to internet tire retailer Tire Rack. That means that a tire inflated to only 25 psi would appear the same as a tire properly inflated, level comparable to the NHTSA hydroplaning test mentioned earlier in this article.
Getting consumers to be more aware of the condition of their tires in general and of the importance of maintaining proper tire inflation pressures has been like the dental profession getting people to floss every day. Luckily there are some community-minded tire retailers in our area like America’s Tire , Firestone, and Pep Boys that offer free tire pressure checks. Click on the company’s link in the previous sentence to see their locations.
In our next installment we’ll look at what you should do in case of a weather-related accident and what supplies you should carry in the car to make that experience safer for you, your passengers, and other drivers on the road.