Today’s Mira Mesa Automotive article focuses on the effect of tire tread depth on braking. When San Diego and La Jolla drivers talk about stopping power, they tend to focus on their brakes. But our tires are where the rubber meets the road. We have to have tires with enough traction to translate braking power into stopping power.
Let’s concentrate on stopping in wet San Diego conditions. In order for a tire to have good contact with the road, it has to move the water out of the way. If it can’t move the water, the tire will actually ride on top of a thin film of water. That’s called hydroplaning and it is a factor in many CA auto accidents. If it’s really bad, you can actually spin out of control. At best, you won’t stop as fast.
Your auto tires have channels for water to flow through. The deeper the channel, the more water it can move. A brand new tire has very deep channels and can easily move a lot of water. As the tire wears down, the channels become shallower and can move less water.When it wears down enough, it can seriously affect your ability to stop on wet CA roads.
That’s why it’s so important for San Diego and Rancho Santa Fe motorists to replace their tires when they get worn. Consumer Reports and other advocate groups call for a standard of replacing tires when the tread is worn down to 4/32 of an inch. That’s 3.2 millimeters. By comparison, you’ve probably seen the wear indicator that’s molded into tires. When tires are worn to 3/32 of an inch, the tread wear bar is visible.
And that little bit of additional tread makes a big difference. Stopping distances are cut dramatically on wet San Diego surface streets and La Jolla highways. A safe stop from CA freeway speeds with 4/32 of an inch of tread would result in a crash with worn out tires.
There’s an easy way to tell when a tire’s worn to 4/32 of an inch. Just insert a quarter into the tread. Put it in upside down. If the tread doesn’t cover George Washington’s hairline, it’s time to replace your tires. With a Canadian quarter, the tread should cover the numbers in the year stamp.
You’ve probably heard of this technique using a penny and Abe Lincoln’s head. That measure gives you 2/32 of an inch – half the suggested amount. And if you have uneven tread wear – have us check it out at Mira Mesa Automotive. It could be a problem with your steering or suspension components or a wheel alignment problem. If you need new tires or have any concerns about your brakes, give us a call today at 858.271.6766.