Tire treads are one of the most essential components of a tire since they determine your tires’ safety, performance, and lifespan.
When checking tire treads, you need to check the tread depth, as there’s a limit that your tires shouldn’t go past to ensure your safety. So, what’s a good tire tread depth? Keep reading to learn more!
What Is A Good Tire Tread Depth?
A good tire tread depth is about 6/32″, and according to the U.S. Department of Transportation, tires should be replaced when they reach 2/32.” Most new tires come with 10/32” or 11/32” tread depths, while others have deeper treads. Therefore, you need to ensure your tires stay within this range before they’re worn out.
For more information about tire tread depth, a good depth for different types of tires and weather seasons, keep reading for more facts and information!
What Is Tire Tread Depth?
Tire tread depth is the vertical measurement between the top of the tire’s rubber parts and the bottom part of the deepest groove.
When driving, the rubber from your treads contact the road and help your car to move forward. Over time, though, these treads wear out and become less effective due to reduced grip and traction.
Your tires can become useless before they’re worn out, and when the depth hits a certain level, the tires become a safety issue because they can’t grip the road properly.
Therefore, as a car owner, your responsibility is to ensure that your tires don’t become too worn out.
Why Do You Need To Check Tread Depth?
Tire tread depth is one of the main tread wear indicators. So, to determine if your tires are well suited for the road, you have to check the depth of the grooves.
Your treads grip the road as you drive; therefore, if they’re not deep enough, your car will lose traction, and you’ll experience problems with braking times.
As well, shallow treads make it hard to control your car when driving on wet and icy roads, which increases your chances of aquaplaning.
What Is A Good Tire Tread Depth?
In the United States, the tire tread depth is measured in increments of 32nds of an inch. When buying new tires, they typically have 10/32” to 12/32” tread depths. However, some off-road cars, trucks, SUVs, and winter tires might have deeper tread depths of up to 15/32”.
According to the U.S. Department of Transportation, car owners need to replace their tires when they reach 2/32“, which is also recommended in most states. Therefore, once your tires hit this number, they need to be replaced.
By the time your tire gets to 2/32″, it’s primarily bald; therefore, it can’t provide the necessary grip on the road. For this reason, your tires become a safety hazard, which makes them illegal to drive on.
When your tires wear down to 2/32”, they will not perform optimally on wet and snow-covered roads. As well, your tires will become prone to heat damage during hot seasons, making them more susceptible to punctures, flats, and tire blowouts.
Therefore, to avoid these types of problems, replace your tires as soon as you can.
A good tire tread depth is 6/32” or higher because the grooves are deep enough to handle any type of road. However, once they start getting to 3/32”, you need to start shopping for new tires because your tires are almost worn out completely.
What’s A Good Tire Tread Depth In mm?
When you buy new tires, the average tire tread depth is about 8 to 9 millimeters.
Once the tires start wearing out, you should keep checking the tread to ensure that they don’t go beyond 2/32”, which is 1.6 millimeters.
In other countries that use metric standards, such as the U.K., the legal tread depth limit is 1.6mm. Therefore, you need to be aware of the correct recommended measurements in your country to avoid legal issues.
What’s A Good Tire Tread Depth For New Tires?
New tires come with a tire tread depth of 10/32 to 12/32 inches. However, there are off-road tires designed for SUVs and trucks that have a depth of about 15/32 inches.
Manufacturers provide these tire depth measurements, but they’re not the same as used tires.
What’s A Good Tire Tread Depth For Used Tires?
If you’re getting used tires, a good tread should be about 90%, which is approximately 5/32” to 8/32”.
Tires in good condition should have at least 6/32″ tread depth for the best performance and safety. Tires with 5/32″ are still sufficient but might start to lose traction when driving on wet roads. However, when the tires get to 4/32″, you should think about buying a new set of tires.
What Is A Good Winter Tire Tread Depth?
According to some manufacturers, winter tires should have a tread depth of at least 5/32 inches (4 millimeters).
Winter tires need to have this deeper depth and be thick enough to handle snowy, icy, and wet conditions. Therefore, when driving during the winter season, your car needs to be equipped with the right kind of tires.
So, If you constantly drive on snow-covered roads, replace your tires once they hit 5/32 inches.
What Is A Good Summer Tire Tread Depth?
If you’re driving on summer tires, the tread depth should be at least 3 millimeters. Afterward, you should get new tires to avoid problems on the road that arise due to high temperatures, such as tire blowouts, punctures, and flat tires.
How To Measure Tire Tread Depth?
Now that we’ve established the good tire tread depth, how can you measure it? This is a common question among car owners and drivers, so here are some of the most common methods to use when measuring tire tread depth:
1. The Penny Test
Place a penny with the head upside down in the shallowest groove with the penny facing you. If the head disappears in between the grooves, your depth is still above 2/32”. However, if you can see the entire head, the tread is worn out and needs replacing.
For the best results, check different tire parts around the circumference and between the tire ribs.
2. The Quarter Tire Test
If you drive in the rain or on wet roads, you need to know much earlier if the tire tread depth is worn out.
Instead of using a penny, you can use a quarter to measure how deep the tread is. Place the quarter with the head upside down into the shallowest tire groove and have the coin facing you.
Just like with the penny test, if the head is visible, your tread is low. However, in this case, you have 4/32” or less remaining.
Note that this test is more suitable for winter tires which need to be replaced much earlier because they need more traction to perform optimally.
3. Indicator Bars
Tires also have indicator bars that help drivers determine how much tread they have left. Indicator bars are molded into most tires and are located at the bottom of the tread grooves around the tire.
Performance, light truck, and medium commercial tires come equipped with indicator bars (also known as wear bars) that are embedded between the tread ribs at 2/32”.
When these bars start appearing worn out, this means that you don’t have more than 2/32″ of tread remaining. Once this occurs, this is a clear indication that you should replace your tires.
4. Tire Tread Depth Gauge
While all these other methods involve a bit of speculation when determining the actual tire tread depth, a gauge will help you get the most accurate reading.
Tire tread depth gauges are readily available at local tire shops and usually cost less than $10; therefore, they’re ideal for getting the correct measurement.
When measuring the depth with a gauge, you need to stick the probe into the tire groove and press the shoulders of the probe against the tread block, which should give you an accurate result (note that all gauges measure the depth in both millimeters and 32nds of an inch).
5. Use A Ruler
If you don’t have a gauge, you can also use a ruler. You can measure the exact amount of tread left by using the 1/16” scale (this measurement is similar to the 2/32”, making it more convenient for measuring).
What Happens When You Have A Low Tire Tread Depth?
Low tire tread depth can become dangerous because it affects how your tires perform, such as the following:
1. Less Traction On Snow or Ice-Covered Roads
When driving on wet or snow-covered roads, you need tires with a tread depth of about 5/32″ or above.
Therefore, if your tires have a depth below this, they increase your chances of hydroplaning and reduce the traction of your tires. Once you can’t control your car with the steering wheel, it becomes quite dangerous to drive.
2. Reduced Stopping Distance
Since your tires don’t have the necessary grip, they’ll have a problem stopping when you apply brakes.
To avoid such problems, always check the tires’ tread depth and have them replaced if they’re worn out.
3. Decreased Acceleration Power
When accelerating, you also need the proper grip on the road. However, if your tire’s tread depth has deteriorated, they won’t accelerate as they should.
4. Decreased Fuel Efficiency
Fuel efficiency is affected when your tires aren’t performing optimally. Since the tires don’t have enough tread, they require more power to move forward.
When this happens, the engine has to work more than usual, using up more fuel. Therefore, to boost your fuel efficiency, ensure that your tires are in perfect condition.
5. Tire Blowout Risks
Your tires could experience a tire blowout, especially when driving in hot weather conditions with worn-out tires.
According to the NHTSA, there were 612 tire-related fatalities in 2019; therefore, it’s critical to have healthy and safe tires to avoid an accident.
If you’re heading into the summer, keep in mind that tires wear out faster, and the asphalt is hot. Therefore, if your tread depth is okay, your tires will last through the season.
Is 9/32 A Good Tire Tread Depth?
New original tires have a tire tread depth of 10/32 and 11/32 inches. Therefore, if your tires have 9/32” depth, they’re still in good condition and can be used for a longer time before they start wearing out.
Is A Tire Tread Depth Of 8/32 Good?
When you start using a new tire at 10/32”, the tire wears out at 2/32”; therefore, your actual usable tread depth is at 8/32”.
At this depth, your tires still have enough traction to drive through different road conditions, meaning you don’t have to replace them quite yet.
How Long Does It Take To Wear Down 1/32” Of A Tire?
Your tires will wear out depending on your tread compound, and on most occasions, your tread will wear down 1/32” for every 5,000 to 8,500 miles under normal driving conditions.
Therefore, the longer you drive and depending on the road conditions, the faster your tread depth wears out. Your tire tread depth lifespan relies on your driving style, weather and road conditions, and the tire rubber compound.
Is The Penny Test For Tires Accurate?
For years, car owners have used the penny test method to measure the tread depth on their tires, and is an accurate indicator of the tread depth left. To confirm the measurement, you can also use a tire tread depth gauge.
To learn more about tires, you can also see our posts on rocks in tire tread, penny in tire tread test, and why do tires has treads.
Conclusion
Tire tread depth is a critical component in tire safety, and a good tire tread depth is approximately 6/32″ or deeper. However, drivers should replace their tires when they reach 2/32″ or 1.6mm because, at this point, the tires can’t grip the road properly.
New tires come with a tread depth of 10/32″ or 11/32″, though off-road cars will have deeper treads. Therefore, as a car owner, you need to constantly measure the tread depth to keep your tires safe on the road and boost performance.