What Is Tire Tread Depth and How to Check It?

How To Tell If You Need New Tires?

When it comes to checking tire tread, there are a number of methods that can help you know if it’s time to replace a tire. The heavily worn tread will prevent a tire from performing as designed and can lead to unsafe driving conditions. One of the simplest, most common ways to check tread depth requires nothing more than a penny and a few moments of your time.

The Penny Test

Place a penny headfirst into several tread grooves across the tire. If you always see the top of Lincoln’s head, your treads are shallow and worn. If this is the case, your tires need to be replaced. If part of Lincoln’s head is always covered by the tread, you have more than 2/32 of an inch of tread depth remaining.

In the United States, tire tread depth is measured in 32nds of an inch. New tires typically come with 10/32” or 11/32” tread depths, and some truck, SUV, and winter tires may have deeper tread depths than other models. The U.S. Department of Transportation recommends replacing tires when they reach 2/32”, and many states legally require tires to be replaced at this depth.

The idea of the penny test is to check whether you’ve hit the 2/32” threshold.           

When performing the penny tire test, remember not only to check each tire but to check various places around each tire. Pay special attention to areas that look the most worn. Even if parts of your tread are deeper than 2/32”, you should still replace the tire when any areas fail the penny test.

Consistent wear around the whole tire is normal, but uneven tread wear could be a sign of improper inflation, wheel misalignment, or a variety of other things. If you see uneven tread wear, you should have a technician inspect your vehicle.

Other ways to check Tire thread

Tread depth gauge

A simple way to check your tire tread depth is by using a tread depth gauge. You can find tire tread depth gauges at your local auto parts store. There are many models available, but an inexpensive simple graduated probe gauge will work just fine.

All you have to do is stick the probe into a groove in the tread and press the shoulders of the probe flat against the tread block and read the result. All gauges should measure in both 32nds of an inch and millimeters.

Tread Wear Indicator Bars

Another indicator of worn-out tread already lives in your tires themselves. Every performance, light truck, or medium commercial tire comes equipped with indicator bars (or wear bars) embedded between the tread ribs at 2/32”. They’re there to help you monitor tread depth and make decisions about tire replacement. Just look to see if the tread is flush with the indicator bars. If they are, it’s time to replace the tire.

Why Check Tire Tread Depth?

With adequate tire tread depth, your car is able to grip the road. This is especially important when roads are snowy or wet, or when you’re driving on less-than-ideal surfaces. Once tread becomes shallow, your tires are more prone to slipping and sliding, creating a dangerous situation for yourself and other drivers on the road.

When your tires are worn, other components of your vehicle can begin to wear prematurely, too, as your vehicle experiences excess strain. While new tires can be a big investment, they’re an investment worth making.

Why Worry About Tread Wear?

The most important reason to worry about tread wear is safety.

When your tire treads are worn, your car may respond poorly to adverse weather conditions like rain and snow. With good treads, your car will grip the road better. Also, having insufficient tread is considered illegal in many states. And finally, worn treads can make other parts of your car wear prematurely.

Potential Problem Areas:

  • Excessive wear in the center tread indicates over-inflation of the tire.
  • Excessive wear on shoulders may signal problems such as under-inflation of the tire.
  • Uneven tread wear indicates poor wheel alignment.
  • Excessive wear on one side of the tire signals an incorrect camber angle.
  • If the treads on the outer section become knobby, it may signal problems with the toe-in value


How to Check Tire Tread Depth?

The tire tread depth gauge measures 32nds of an inch. Good tire tread depth will be 6/32 or deeper. If the depth is 4/32, you should start thinking of replacing your tires and getting new ones. 2/32 or less means that you should change your tires ASAP.

Do I need to replace tires at 4 32?

If your gauge measurement reads: 6/32″ or higher: Your tire’s tread depth is sufficient. 5/32″: If snow-covered roads are a concern, you should consider replacing your tires. 4/32″: If you frequently drive on wet roads, consider replacing your tires.

How good is 7 32 treads?

Used tires tread can be up to 90%, but the average is 6-8/32”. Tires in good condition should have a minimum of 6/32” to be useful, or 4/32” if the tire is 13-14”. The average legal minimum tread depth is 2/32”, but driving becomes unsafe with such a tread.

What tire depth should you replace your tires?

The U.S. Department of Transportation recommends replacing tires when they reach 2/32”, and many states legally require tires to be replaced at this depth. The idea of the penny test is to check whether you’ve hit the 2/32” threshold. Here’s how it works: Place a penny between the tread ribs on your tire.

How good is 6 32 treads?

6/32” Your tire’s tread depth is sufficient for 3-seasons but nearing the minimum for a winter tire. 5/32” If wet roads are a concern, consider replacing your tires. 4/32” – 3/32” Seriously consider replacing your tires as soon as possible.

Is 5mm tire tread good?

If the red is visible the tire tread is below 1.6mm. This means the tire is 100% worn and should be replaced urgently. If the orange is visible, the tire tread is 3mm which is the recommended minimum. If the green is visible, the tire tread is above is 5mm and is safe to drive.

Why do new car tires wear out so fast?

The tire manufacturer bears that responsibility. The OEM tires that came with your car can’t be replaced (which is a good thing) after they’ve worn out. And they will wear out much sooner than they should. This is because virtually all auto manufacturers specify very soft rubber which means they wear out too fast.

When should tires be replaced mileage?

Most tires are considered to have a life of between 25,000 and 50,000 miles before they need to be replaced.

Should I replace my tires at 7 32?

“Tire Rack’s advice is that if rain and wet roads are a concern, you should consider replacing your tires when they reach approximately 4/32″ of remaining tread depth.” Obviously, the tread will wear away over the life of the tire and the volume of its tread grooves will be reduced.

What does 7 32 means on a tire?

These are imperial measurements of the depth of the grooves. in the tread or wear surface of a tire. 7/32″ = .21875″ (5.556 mm) 9/32″ = .28125″ (7.144 mm) and so on.

Are 7 32 winter tires, OK?

Read the scale. If you’ve got a number between 7 and 12/32” – you’re good for now! Any less, and you’ll be able to improve your winter braking and cornering with a new set of winter tires.

Should I change all 4 tires at once?

It’s always best to replace all 4 tires at the same time. This is because all 4 tires spin independently of one another, and different tread depths and/or styles can cause them to spin at different speeds. That could potentially damage the drive train, and possibly affect an indirect TPMS system if the vehicle has one.

Should tires be replaced after 5 years?

After five years or more in use, your tires should be thoroughly inspected at least once per year by a professional. If the tires haven’t been replaced 10 years after their date of manufacture, as a precaution, Michelin recommends replacing them with new tires.

How many 32nds are new tires?

New tires have an average tread depth of 8 to 9 millimeters (10/32 to 11/32 inches). As you drive, the tread will wear down. A tire with a tread depth below 1.6 millimeters (2/32 inches) lacks grip. Braking distance and vehicle control are impaired.

How many 32nds is a penny?

A penny is obviously smaller than a quarter though, and so is the distance from the edge of the coin to the top of the head. On a quarter, it’s about 4/32nds of an inch but on a penny, it’s 2/32nds, which happens to be the minimum legal tread depth in most states.

Is 50 percent tire tread good?

If the tread reaches the bear’s paws, your tires are probably pretty new. If it reaches all the way across the silver, they’re about 50% worn. If your tire tread reaches only about halfway into the letters, it’s time to shop for new tires.

Is 3mm tire tread safe?

For summer tires, the remaining tread depth must be no less than 3 mm, and for winter and all-season tires it must be no less than 4 mm. smaller tread depth may become critical on wet pavement, slush or snow.

How long will a 1mm tread last?

“With just 1mm of tread remaining a car’s stopping distance is 250m. If tires are not changed before they wear to 1.6mm drivers may be compromising the safety of themselves and other road users.”

Is 3mm tire tread, OK?

Tire and safety experts believe the 1.6mm legal minimum is insufficient to guarantee safety most recommend a minimum tread depth of 3mm for tire replacement. Tests by UK technical organization MIRA found that, once tires are below 3mm, stopping distances increase dramatically.

Do tires wear faster on highway?

All things considered; tires will wear out slower on the highway than they will be driving through town. Highway driving typically involves less braking as opposed to city driving. Braking and acceleration will lead to faster tire wear.