What You Need To Know About Checking Your Tire Tread
Your tire is the only part of your vehicle that touches the road. At least I hope so. If it’s not, you’ve definitely got some other ‘How To’s’ to read. Checking the tread wear, and the overall health of your tire on a regular basis, can make the difference between sitting on the roadside changing putting on a spare tire, or making it to work on time.
Checking your tires tread depth and tire pressures go hand in hand. I recommend checking both at least once a month to make sure your tires are still safe to be cruising on. There’s nothing worse than a surprise tire light, or an even more surprising flat tire, that could have been avoided by checking your tires tread and pressures once a month.
Tire maintenance is one of the most important aspects of owning a vehicle. After handling various tire repairs and replacements over my career, I’ve come to find that your tires are really the most important part on your vehicle. Just the same as any other major component, if you don’t have safe and well-maintained tires, you’re probably not going to make it very far down the road at all.
Tire tread is easy to measure as you’ll find in this guide. Tire tread measurements in the United States are made by 32nds of an inch. With most new tires tread depth being around 10/32nds, they will give you plenty of grip going down the road. However, once you reach 4/32nds, your tires grip on the road has faded, and you’ll be facing some potential traction and handling issues if you go much further. Once you’ve reached 2/32nds, it’s time for replacement as soon as possible.
Checking Your Tires Tread Will Keep You Safer On The Road
I’ve spent countless hours on the side of the road changing out spares, only to find out the driver rarely checked their tire tread, and in some cases, wore their tires all the way down to the point where the tire was actually leaking air through the tire cords themselves! Needless to say, these types of drivers don’t belong on the road. They cause a hazard to themselves and others. Don’t be one of those drivers.
The bottom line is, we’re trying to help you keep your vehicle on the road for longer. Without knowing the proper way to check your tire tread depths, and overall wear in general, can leave you on the side of the road in a hurry, and even to turn you into a hazard for yourself and others. We don’t want that, and I know you don’t either.
Have Peace of Mind Knowing Your Tires Are In Good Shape
Many vehicle owners are afraid to check their tires tread, dreading that big expense of having to get new tires. Most of the time, checking your tire tread wear and overall health is one of the easiest and best things you can do for your vehicle and yourself. Having that peace of mind knowing your tires are going to make it to their destination is one of the best kinds of reassurance you can have for your vehicle.
Once you look at the numbers and see that there are 15,000 tire-related crashes a year, you might just want to take the time to give those tires a once over with this helpful guide. With risks of hydroplaning and other traction and handling-related mishaps due to worn-out tires, it’s always good to know you might not be another statistic. I don’t like using scare tactics to get you to inspect your vehicle, I’m just stating the facts of the matter. Tire-related crash rates at any number can be avoided by following this simple guide.
Save Money By Being Able to Budget Out Your Tire Replacement
Knowing your current tread depth, and in turn, knowing approximately when your tires will need to be replaced, will keep you from having that surprise expense and immense concern of a mechanic telling you that your current tires are unsafe and that you need new tires that day. Checking your tire tread depth and overall wear will give you time to make that investment in your new tires.
The average American drives around 15,000 miles a year. When new tires are installed on your vehicle, on average, they will last around 60,000 miles before needing replacement, depending on the tire. That is if you’re not doing burnouts in your local parking lot, and peeling out from every red light. With those numbers, that means you’ll have about four years before your tires need replacing, give or take a year depending on your driving habits. Safe driving should always be a standard practice, especially if you want to maintain the life of your tires.
Supplies You’ll Need For Checking Your Tires Tread
For some, this may be a surprising list of special tools you need for checking a tire. But trust me, it’s worked for years, and it will work for you too.
- A Penny
- A Quarter
- A Tire Tread Depth Gauge
How To Check Your Tires Tread (4-Step Guide)
- Tire Wear Indicators (Wear Bars)
- The Penny Test
- The Quarter Test
- Using a Tread Depth Gauge
Step 1: Tire Tread Indicators (Wear Bars)
Now, before we go putting some presidents heads inside the grooves of your tires, or running up to the auto parts store for a tread depth gauge, you can check to see if your tires are worn out by doing a quick visual check to see if they are down to, or very close to, the wear bars.
Tread wear indicators, or most commonly known as wear bars, are horizontal lines molded into the bottom tread of the tire. One of your best indications for needing tire replacement is already built in to your tire. However, in good tire maintenance, you never want your tire tread to make it down to the wear bars.
Most manufacturers design the wear bars to become flush with your tread at 2/32nds of an inch, indicating you need replacement. If you can see your wear bars are almost flush with the tread of your tires, don’t go digging through your cup holder for coins for the rest of this guide, go digging for a reputable tire shop or service station where you can get your tires replaced.
I personally have always started to recommend replacement at around 4/32nds of an inch. The tires may still have some life left, but at 4/32nds, the tire has lost a considerable amount of traction already, and the last thing you want to do is put them off to the point where you make it down to your wear bars. In heavy rain, without a good tread depth, the tire can’t move nearly as much water through the treads, which can cause your vehicle to hydroplane, as well as multiple other handling and traction issues.
While you’re down there inspecting your tires wear bars, and while continuing with this tread inspection guide, it is also a great time to check the overall condition of your tires. Performing a visual inspection can save a headache of a flat tire or even a blowout. Check for any dry cracking around the sidewall of your tires and any damage to your sidewalls as well, such as slits or major dry cracking in the rubber. Dry rotting can lead to tires blowing out, especially at higher temperatures and speeds.
If you’re able, you can also take a look in the tread for any metal debris in your tire, like screws or chunks of metal. If you find any debris, don’t pull it out, as it may cause your tire to start leaking if it isn’t already. Make sure to schedule service at your local tire or service center as soon as possible.
Step 2: The Penny Test
It may seem kind of strange to some, but using some good old fashioned American currency can actually give you an accurate reading of your tires tread depth. With American coin currency being the same size and shape over the last 60 years or so, they are pretty much always going to be an accurate way to measure tire tread depth. The reason you can use a penny, is because the distance between the top of the penny and Lincoln’s head is about 2/32nds of an inch. Just make sure the penny you grab is in decent shape. That old worn out penny you’ve been holding on to from 1961 that’s corroded around the edges might not be the most accurate option.
First, we’re going to start with the penny test. Using the penny will tell you if you have more than 2/32nds of an inch left on your tire tread, which is the lowest that the U.S. Department of Transportation recommends before you need to find tires. In some states, 2/32nd’s of an inch is actually considered legally worn out.
Performing the penny test is about as simple as it gets when it comes to checking your tread. Take the penny, and place it inside of your tires tread groove, with the top of Lincoln’s head facing straight down towards the tire. Now, take a look at the top of his head. If you can see the top of his curly alloy locks, the tires you’re looking at are worn out to below 2/32nds of an inch. Repeat this process across all of the treads of your tire. You may find your tread is deeper in some areas, or more shallow. If this is the case, your tire may be wearing unevenly, and an alignment and suspension component check along with those new tires is probably needed.
If you’ve found the top of Lincoln’s head is visible across your tire, or even if it’s only visible in one or two treads, I would make a call to your local reputable tire shop as soon as you can and have them check their schedule, because the tires you’re driving on are considered unsafe by the U.S. Department of Transportation, and most state laws as well.
If your tread is covering Lincoln’s face, or you can see your wear bars have become almost flush with your tire’s tread, then your tires are still considered legally safe, but keep in mind, your tire may have still lost considerable performance, even if it is above 2/32nds of an inch. That’s where our quarter test comes in.
Step 3: The Quarter Test
The second coin method is the quarter test. Using the quarter to measure your tread depth will tell you if your tires have worn to, or have a minimum of at least 4/32nds of an inch. This is because the distance between the top of the quarter and top of Washington’s head is 4/32nds of an inch. Keep in mind, this is also a great time to check the overall condition of your tires.
The quarter test is performed identically to the penny test. Place the quarter inside of your tires tread groove with the top Washington’s head facing straight down toward the tire, repeating the process across your tire tread. Now take a close look at the top of his head. If you can see the very top of Washington’s head, that means your tires have worn past 4/32nds of an inch, which isn’t bad, but you should start thinking about replacement within the next month or two, especially if winter or wet season is coming up.
If you do live in a heavy snow area, you may have winter tires installed on your vehicle as well, or sitting around your garage waiting for that first snowfall. The coin method works on those as well, just make sure if you have studs installed in the tires that you take a close look at their condition, along with your tread depths. Now is also a good time to check your spare tire tread too. If you’ve bought a used vehicle, you never know how that spare was used, and you’ll want to check the tread life on it as well, just in case the last owner decided to wear it out.
Step 4: Using A Tire Tread Depth Gauge
A standard tool for any vehicle technician and responsible owner alike is the tread depth gauge. I’ve had one since my first day in the vehicle maintenance industry. I’ve also owned many different styles over the years, ranging from the standard ‘analog’ style, to the fancy digital gauges that claim to be more accurate. I’ve always stuck with the standard style myself, it’s pretty foolproof, and you don’t have to worry about an electronic malfunction or searching around for replacement batteries.
Using the tread depth gauge to measure your tires tread depth can give you a bit more accurate read on your tire life than using a two presidents to do the job. You can find them at your local auto parts store, and maybe even at some gas stations as well. It may even be the cheapest thing your auto parts store has to offer, aside from those air fresheners that always seem to lose scent as soon as you hang them off your rear view mirror.
Using a tread depth gauge is pretty straightforward and easier to read than the quarter or the penny. Most gauges read tread depth in both millimeters and 32nds of an inch. In our case, we’ve been using 32nds of an inch as measurement in our guide because we’re based in America.
Take your tread depth gauge, push all the way down on the top part with the number indicators, and you’re ready to check some tread depths. While holding the body of the tread depth gauge, not the top indicator, align the small indicator dial at the bottom between your tires treads. Push the body of the gauge down flush with the tire, and make sure not to touch the top depth indicator. The gauge indicator will now move upwards inside of the body of the gauge. Remove the gauge from your tire without touching the top indicator, and you’ll have your measurement. The line where the indicator meets the top of the body of the gauge is your measurement.
As with the coin tests, repeat this process along your tires tread, so you’re able to see the overall depth of your tire. You want to see more than 2/32nds of an inch of tread across all of your tires to be within the U.S. Department of Transportation guidelines, and most state laws as well. If you see uneven wear across the tire, make sure you get an alignment check with your next tire purchase. You’ll also want to have your suspension inspected for any loose or damaged components, as they could also be causing abnormal tire wear. Loose tie rods, control arms, ball joints, or even bad shocks, can cause abnormal tire wear.
As with the coin tests, now is also a great time to check overall condition of your tire, and to make sure there’s no road hazards sticking out of your tires tread. If there is, don’t pull it out. Schedule a service at your local tire shop or trusted service station as soon as possible.
Other Valuable Resources on Checking Your Tires Tread
Checking your tire tread and overall tire wear can save you a massive amount of headache down the road. From peace of mind to budgeting out your replacement, you’ll have no problems if you do that once a month check on your tires.
Here are a few more resources I’ve found that go further in depth for information on your tires tread depths:
- https://www.goodyear.com/en-US/learn/tire-basics/how-to-measure-tire-tread-depth
- https://www.nhtsa.gov/equipment/tires#:~:text=Tires%20are%20not%20safe%20and,in%20between%20the%20tire’s%20tread.
- https://www.federalregister.gov/documents/2019/12/19/2019-27209/federal-motor-vehicle-safety-standards-tires
