Back to all

How Much is Enough for Royal Oak Auto Owners? Tire Tread Depth

December 31, 2023

Most Royal Oak drivers know that tires wear out and that the wear has to do with tread depth. Most of us have heard that “bald” tires are dangerous, but most of us picture a tire with no tread at all when we think of a bald tire. And when we take our vehicles in for preventive maintenance, the technician tells us they're need to be replaced long before all the tread is worn off. Just how much tire tread wear is too much? And how can you tell? Tires are and their condition is important to the safe handling of a vehicle, so it's for Royal Oak vehicle owners to know the answers to these questions.

First of all, it's important to understand that there may be a legal limit to tread wear. If your tires are worn past this limit, you have to replace them to be in compliance with Michigan auto safety laws. That's why measuring your tread wear is part of a vehicle safety inspection.

In some jurisdictions, tread must be at least 1.6 millimeters or 2/32 of an inch thick. This standard has been in effect since 1968. But this standard has recently been called into question, and some Michigan professionals are arguing that it be changed.

The safety issue that has brought this standard under scrutiny is the ability of a vehicle to stop on a wet surface. When a vehicle has trouble stopping, most Royal Oak drivers immediately look at the brakes as the source of the problem. But tires are crucial to safe stopping distances because they provide the traction required in a stop.

A tire's contact with the road surface creates traction, which allows for effective braking. On a wet surface, a tire only has traction if it can get to the road's surface. So tire tread is designed to channel water out from under the tire to allow it to stay in contact with the road. If the tire can't shift the water, then it starts to “float.” This condition is called hydroplaning. It is very dangerous for Royal Oak drivers since the vehicle won't stop no matter how hard the driver presses the brakes. Steering control is also lost.

A recent study tested the stopping ability of a passenger car and a full-sized pick-up on a road surface covered with only a dime's depth of water (less than a millimeter). The vehicles were traveling at 70 mph (112 kph) when they stopped on the wet surface. At 2/32 (1.6 mm) tread depth, the stopping distance was double that of a new tire. The passenger car was still traveling at 55 mph (89 kph) when it reached the stopping distance it experienced with new tires.

Let's suppose that you're on a busy Royal Oak road in a light drizzle and a vehicle stops suddenly in front of you. You just bought new tires and you brake hard, missing the vehicle with only inches to spare. If you hadn't bought those new tires, you would have crashed into that vehicle at 55 mph (89 kph). That is a major difference.

What if your tires had a tread depth of 4/32 (3.2 mm)? You would have crashed into that vehicle at 45 mph (72 kph). Still not a good situation. But it's better.

Now what if you were driving that pick-up truck? You wouldn't have missed that vehicle in the first place, and you would have crashed at higher rates of speed in both of the other scenarios. The heavier your vehicle, the longer its stopping distance. It's a matter of physics.

The results of this test has led Consumer Reports and others to ask that the standard for tread wear be changed from 2/32 (1.6 mm) to 4/32 (3.2 mm). The increased standard will improve safety on the road and save lives here in Michigan and nationally.

Of course, until the standard changes, you'll have to decide whether you'll be willing to replace your tires a little sooner.

You can use an American quarter to tell if your tread wear is down to 4/32 (3.2 mm). Place the quarter into the tread with George's head toward the tire and his neck toward you. If the tread doesn't cover George's hairline, you're under 4/32 (3.2 mm). With a Canadian quarter, the tread should cover the digits of the year.

You can measure the 2/32 inch (1.6 mm) tread wear with a penny. If the tread touches the top of Abe's head, it's at 2/32 (1.6 mm). Tires are super important when it comes to vehicle care. But their condition has a major impact on safety. We need to decide whether to sacrifice safety for economy. Keeping our tread wear above 4/32 in (3.2 mm) is good auto advice.

TLC Custom Exhaust Brakes & Tires
1735 N Main St
Royal Oak, Michigan 48067
248-541-8300
tlcautocareroyaloak.autotipsblog.com

Need Service?

More articles from TLC Auto Care

The Light Nobody Wants to See (Check Engine Light)

April 28, 2024

You've probably had your Check Engine Light go on. Then it goes off and you figure, hey, whatever the problem was, it's gone now and I don't have to worry about it. Well, the problem may have gone away and it may not have. Your vehicle likely has one of these warning lights on the instrument pa... More

Fuel Saving Tip: Car Weight and Your Michigan Driving

April 21, 2024

Weight is the enemy of fuel economy. Everyone from Royal Oak knows this makes sense.Some of us in the Royal Oak area carry a bunch of unnecessary weight, and I'm not talkin' what you see in the mirror.Guys: sports equipment and tools. Ladies: well, just take a look around the passenger compartmen... More

Read a Good Tire Lately? (Tire Wear)

April 14, 2024

There's lots of good information to read in books and online. You might not know that you can also "read" your tires and learn a lot about what shape they're in and if they are in need of attention. It's important to know how your tires are doing because a tire failure can be very dangerous to y... More