One question that many Minnesota and North Dakota drivers have about their vehicles is when they should replace their tires. For many, the answer is “when they no longer pass a safety inspection.” While it makes sense that you’d want to get the most use out of your tires as possible, waiting too long can have a serious impact on your safety. We’ve all heard that “bald” tires are dangerous, but when we think of a bald tire, most of us picture a tire with no tread at all.

So how much tire tread wear is too much? And how can you tell?

Uneven Regulation

It might surprise you to know there are no official federal regulations for tread depth in the U.S. However, 42 states, and all of Canada, do have individual regulations. They consider 2/32 of an inch – or 1.6 millimeters – to be the minimum legal tread depth. Two other states, including California, consider only 1/32 of an inch to be the minimum, and six states have no legal tread depth standards at all.

Since 1968, U.S. law has required that a raised bar be molded across all tires. When tires are worn enough that this bar becomes visible, there’s just 2/32” of tread left. But automotive technology has grown leaps and bounds since that time. So does this older standard give you enough safety?

A Call for New Standards

Recently, Consumer Reports has conducted braking studies under a variety of road conditions, and based on their findings they have issued a call to consider replacing tires when their tread is worn to only 4/32”. The main reason for the change is due to the challenge of braking on wet surfaces.

When it comes to our vehicles, we tend to think it’s the brakes doing all the stopping. That’s not necessarily true. Traction with the road is equally important, so you also need to have effective tires to fully stop your vehicle. When conditions are wet or snowy, the tread of the tire is absolutely critical to stopping power.

A Little Tread Goes a Long Way

Picture this: You’re driving over a wet stretch of road. Obviously, you know your tires need to be in full contact with the road in order to stop. That means each tire has to channel the water on the road away as you drive. Otherwise, they are actually floating on a thin film of water – a condition known as hydroplaning. When there’s not enough tread depth on a tire, it can’t move that water out of the way and you start to hydroplane, which is incredibly dangerous since the vehicle won’t stop no matter how hard you press the brakes. Steering control is also lost.

So, how do you know when your tires are at 4/32”? There’s a simple test you can do at home to check. Just insert a quarter, upside-down, into the tread of each tire. If the tread doesn’t cover George Washington’s hairline, it’s time to replace your tires. With a Canadian quarter, the tread should just cover the numbers in the year stamp. Older readers may remember doing this same trick, but with pennies. However, a penny only gives you 2/32” of an inch to Abraham Lincoln’s head. To meet the new (suggested) standard, only a quarter will do.

Put Your Tires in the Care of a Kennedy Specialist

Tires are a big ticket item, and people want to get the most use they can from them in order to maximize their value. But when you think about it, is the extra risk really worth running your tread all the way down to the legal limit? For us at Kennedy Transmission – and we would guess for many readers – the answer is “no.” So if you think your tires might be nearing the end of their life and want a professional opinion, bring them by your local Kennedy Transmission shop and let us take a look. Use our online shop locator to find a facility nearest you.

© 2017 Kennedy Transmission Brake & Auto Service

Contact Phone: 952.476.4338 Visit the store locator page for direct location phone numbers