Tires don't fail all at once. They lose grip a little at a time, and most drivers don't notice until the first rain turns the 405 into a skating rink. The good news: you can find out where your tires stand in about five minutes, in your own driveway, with pocket change.
Run these five checks on all four tires. Then use the chart at the end to decide what to do next.
1. The penny test: are your tires worn out?
Place a penny upside down in a tread groove, with Lincoln's head pointing into the tire.
- You can see the top of Lincoln's head: the tread is at 2/32 of an inch or less. The tire is worn out. Replace it.
- Part of Lincoln's head is covered: you're above 2/32. Move on to the quarter test.
Check at least three spots on each tire: the inside groove, the center, and the outside groove. Tires often wear more on one edge than the other, and the worn spot is the one that counts.
California's legal minimum is 1/32 of an inch. That's the point where a ticket is possible, not the point where a tire is safe. The penny test flags tires at 2/32, which is where we recommend replacing.
2. The quarter test: should you start shopping?
The penny tells you when a tire is done. A quarter tells you when it's getting close. Place it upside down in the same grooves, with Washington's head pointing into the tire.
- You can see the top of Washington's head: the tread is at 4/32 of an inch or less. The tire is still legal, but it has lost much of its ability to push water out of the way. Start pricing replacements now.
- Washington's head is partly covered: you have more than 4/32. You're in good shape for tread.
Why 4/32 matters here: Long Beach can go months without rain, so oil builds up on the road. The first storm lifts it to the surface, and worn tires hydroplane at lower speeds than you'd expect. Read more in First Rain in Long Beach: Are Your Tires Ready?
3. The wear bars: a built-in gauge
Every passenger tire has small raised bars molded across the bottom of the tread grooves. They sit at 2/32 of an inch. When the tread wears down flush with those bars, the tire is at the end of its life, which is the same answer the penny gives you.
If you see the bars level with the tread in any spot, the tire needs replacing, even if the rest of the tire looks deeper.
4. The date code: how old are your tires?
Tread depth is only half the story in Southern California. Heat off the pavement and year-round sun break down the rubber, and a tire can age out long before it wears out. That's especially true on cars that sit a lot or only do short trips.
Find the letters DOT on the sidewall. The last four digits after it are the week and year the tire was made. For example, 2319 means the 23rd week of 2019.
- Under 6 years old: age isn't a concern on its own.
- 6 years or older: have the tire inspected, even if the tread passes both coin tests.
- 10 years or older: replace it, including the spare.
For the full breakdown of how SoCal heat affects tire life, see How Long Do Tires Last in Southern California?
5. The sidewall walk-around: cracks, bulges, and cords
Crouch down and look at the side of each tire, inside and out. Turn the steering wheel all the way to one side to see the inner edge of the front tires.
Small surface cracks
Fine cracks in the sidewall are dry rot, from heat and UV. Light cracking on an older tire means replacement is coming soon.
A bubble or bulge
The internal cords have broken, usually from a pothole or curb. This can't be repaired and can blow out at speed. Why a bubble means replacement.
Exposed cords or wires
If you can see fabric or steel through the rubber anywhere on the tire, stop driving on it.
While you're down there, look at how the tread is wearing. If one edge is much lower than the other, or the tread has a wavy, scalloped feel, the tire is wearing unevenly. New tires won't fix that on their own. See what's causing uneven tire wear.
What you feel from the driver's seat
Some tire problems show up in how the car drives before they show up in a coin test:
- A vibration in the steering wheel at freeway speed
- The car pulling to one side on a straight road
- More road noise than there used to be, especially a rhythmic hum
- A tire that needs air more than once a month
- Sliding or a long stop on wet pavement
Any of these is worth a look. A tire that loses air slowly often has a nail in it, and a tread puncture is usually repairable, starting at $25.
Your results: keep driving, start shopping, or come in
| What you found | What it means | What to do |
|---|---|---|
| Washington's head is covered, tires under 6 years old, clean sidewalls | Your tires are in good shape. | Check again in 3 months, and before any long trip. |
| You see Washington's head but not Lincoln's | Tread is between 2/32 and 4/32. Wet grip is dropping. | Start shopping. Replace before the rainy season if you can. |
| Tires are 6+ years old, or light sidewall cracking | The rubber is aging, even if the tread is fine. | Bring it in for a free tread check. |
| You see Lincoln's head, or the tread is flush with the wear bars | The tire is worn out. | Replace now. |
| A bulge, exposed cords, or a tire that won't hold air | The tire is unsafe to drive on. | Come in today. Keep speeds low on the way. |
Not sure what you're looking at? Get a free tread check
Coin tests are a good screen, but they're not perfect. Uneven wear can hide on the inner edge, and some damage is easy to miss on a black tire in a dim garage. If you're not sure, stop by either of our Long Beach shops for a free tread check. We'll put a tread gauge on each tire, check the date codes and sidewalls, and show you the readings before we recommend anything. No appointment needed, and no obligation to buy.
If you do need tires, we'll quote budget, mid-range, and premium options side by side with the out-the-door price. We keep popular sizes on hand and can get almost any tire same day or next day. See what 4 tires cost in Long Beach, or visit our Cherry Ave or Paramount Blvd location. Walk-ins are welcome, and Cherry Ave is open 7 days a week.
Frequently Asked Questions
How do I do the penny test on my tires?
Put a penny upside down into a tread groove, with Lincoln's head pointing into the tire. If you can see the top of Lincoln's head, the tread is at 2/32 of an inch or less and the tire is due for replacement. Check several grooves across the tire and on all four tires, because tires rarely wear evenly.
Is the penny test accurate?
It's accurate enough to catch a tire that's at the end of its life. The top of Lincoln's head sits about 2/32 of an inch from the edge of the penny. It won't warn you early, though. For that, use a quarter: the top of Washington's head is about 4/32 of an inch from the edge, which is when wet-road grip starts to drop off noticeably.
What is the legal minimum tread depth in California?
California law requires at least 1/32 of an inch of tread on passenger car tires. That is a legal floor, not a safe target. Most tire makers and shops recommend replacing at 2/32, and at 4/32 if you drive the freeways in the rain.
My tires have plenty of tread. Can they still need replacing?
Yes. In Southern California, heat and UV age tires faster than the tread wears down. A tire with deep tread can still have dry rot, sidewall cracks, or a bulge. Check the four-digit DOT date code on the sidewall: if the tire is 6 or more years old, have it inspected even if the tread looks good.
Do I have to replace all four tires at once?
Not always. On most two-wheel-drive cars you can replace two at a time, and new tires go on the rear. All-wheel-drive vehicles are pickier, because tread depths that don't match can strain the drivetrain. Tell us the vehicle and we'll tell you what it needs.
What if I can't tell whether my tires are OK?
Stop by either Long Beach shop for a free tread check. We'll measure the tread with a gauge, check the date code and sidewalls, and show you what we see before we quote anything. If the tires still have life left, we'll tell you that.
Have this problem right now? Our Cherry Ave shop is open 7 days a week and Paramount is open Monday through Saturday — no appointment needed for most services.