Check your tire tread depth first

The most reliable way to know if you need new tires is to measure how much tread remains. Tire tread is the grooved rubber that grips the road — as you drive, it wears down gradually. When tread gets too shallow, your tires lose grip, especially on wet pavement, and your brakes take longer to stop the car.

Use the penny test to check tread depth yourself. Take a penny and insert it into the tread groove with Lincoln's head upside down and facing you. If you can see the top of Lincoln's head, your tread is too worn and you need new tires. If the tread covers part of his head, you still have usable tread. This test works because the distance from the edge of a penny to the top of Lincoln's head is about 2/32 of an inch — the legal minimum tread depth in most U.S. states.

For a more precise measurement, buy a tread depth gauge at any auto parts store for $5 to $15. Press the gauge into several grooves around each tire. Write down the numbers. If any tire reads 2/32 of an inch or less, that tire needs replacing. Many tire shops will also measure your tread depth for free.

Key Takeaways

  • The penny test and tread depth gauge both measure whether your tires have worn down to 2/32 of an inch, the legal minimum.
  • Visible damage — cracks, bulges, or objects embedded in the rubber — means you need a new tire when ready, even if tread depth is acceptable.
  • Uneven wear across the tire surface often signals an alignment problem, and replacing tires without fixing alignment will wear out the new ones quickly.
  • Most tires last three to five years or 25,000 to 50,000 miles, whichever comes first, though this varies by tire quality and driving conditions.
  • If you are unsure whether a tire is safe, a tire shop can inspect it in minutes and tell you whether replacement is necessary.

Look for visible damage and wear patterns

Beyond tread depth, inspect each tire for signs of damage. Walk around your car and look at the sidewall and tread area of all four tires. Cracks in the rubber, bulges or blisters on the sidewall, or cuts deep enough to see the inner layers all mean the tire has lost structural integrity and needs replacement when ready. A bulge indicates the inner structure has failed and the tire can blow out without warning.

Also check whether the tread is wearing evenly across the tire. Run your hand across the tread — it should feel roughly the same height all the way around. If the outer edges are noticeably more worn than the center, or vice versa, the tire is wearing unevenly. This usually means your wheels are out of alignment or your suspension needs attention. Replacing tires without fixing the underlying problem will wear out the new tires in the same pattern.

If you find an object embedded in the tire — a nail, screw, or piece of metal — do not assume the tire is ruined. Small punctures in the tread area can sometimes be patched by a tire shop. Punctures in the sidewall cannot be safely repaired and require a new tire.

Understand how age and mileage affect tire life

Even if tread depth is acceptable, tires degrade over time. The rubber compounds harden and lose flexibility, which reduces grip and increases the risk of cracking. Most tires last between three and five years from the date of manufacture, regardless of how many miles you have driven. If your tires are older than five years, consider replacing them even if the tread looks fine.

You can find the tire's age by looking at the sidewall for a code called the DOT number. The last four digits of this code indicate the week and year the tire was made. For example, "3521" means the tire was made in the 35th week of 2021. Count backward from today to see how old the tire is.

Mileage also matters. Most tires are rated to last between 25,000 and 50,000 miles, though premium tires may last longer. Check your tire's sidewall for a treadwear warranty number — this is a rough estimate of expected lifespan. A tire rated 40,000 miles should last roughly 40,000 miles under normal driving conditions, though actual mileage varies based on your driving habits, road conditions, and how well you maintain tire pressure.

Check tire pressure and condition regularly

Underinflated tires wear out faster and are more prone to damage. Check your tire pressure once a month and before long trips. The correct pressure for your car is printed on a label inside the driver's door jamb, not on the tire itself. The number on the tire is the maximum pressure, not the recommended pressure.

Use a tire pressure gauge to check pressure when tires are cold — meaning the car has been parked for at least three hours or driven less than a mile at low speed. Tire pressure rises as tires heat up during driving, so a warm-tire reading will be higher than the actual pressure. If pressure is below the recommended level, add air at a gas station or tire shop. If pressure keeps dropping, you may have a slow leak that needs repair.

Overinflated tires also wear unevenly, wearing faster in the center. If you consistently find your tires overinflated, check whether you are adding air based on the maximum pressure printed on the tire rather than the recommended pressure on the door jamb.

Know when to replace one tire versus all four

If only one tire is damaged or worn, you may not need to replace all four. However, the replacement tire should match the tread depth of the other tires as closely as possible. If your other three tires have significant tread remaining, installing a new tire with full tread on one wheel can cause handling problems and uneven wear.

If all four tires are wearing evenly and approaching the end of their life, replacing all four at once is usually the best choice. This ensures consistent grip and handling. If only one or two tires are damaged, ask the tire shop whether the remaining tires have enough tread to stay safe. They can advise whether a partial replacement or full replacement makes sense for your situation.

All-wheel-drive vehicles sometimes require all four tires to be replaced together because mismatched tire sizes can damage the transmission. Check your owner's manual or ask your tire shop whether this applies to your car.

Understand what happens if you drive on worn tires

Driving on tires with insufficient tread increases your stopping distance, especially on wet roads. In wet conditions, a car with tread below 2/32 of an inch can take 40 percent longer to stop than a car with new tires. This extra distance can mean the difference between avoiding a collision and hitting another vehicle or pedestrian.

Worn tires are also more likely to hydroplane — a condition where the tire loses contact with the road surface on wet pavement and the car skids uncontrollably. Bald or nearly bald tires cannot channel water away from the contact patch, so the tire floats on a thin layer of water.

In many states, driving on tires worn below 2/32 of an inch is illegal and can result in a traffic citation. Insurance companies may also deny a claim if an accident occurs and the investigation shows your tires were below legal minimum tread depth.

Frequently Asked Questions

How much does it cost to replace tires?

Tire cost varies widely based on tire size, brand, and quality. Budget tires may cost $50 to $100 each, while mid-range tires typically cost $100 to $200 each, and premium tires can cost $200 to $400 or more per tire. Installation and balancing usually add $15 to $30 per tire. Many tire shops offer discounts when you replace all four tires at once.

Can I replace just two tires instead of four?

Yes, but the two new tires should be installed on the rear axle if your car is front-wheel drive, or on the front axle if your car is rear-wheel drive. This helps prevent loss of traction. The new tires should match the tread depth of the existing tires as closely as possible. Ask your tire shop for guidance on your specific vehicle.

What is the difference between all-season and winter tires?

All-season tires are designed to perform adequately in most conditions year-round. Winter tires have a different rubber compound and tread pattern that provides better grip in snow and ice. Winter tires wear faster in warm weather and are more expensive, so many drivers use them only during winter months and switch back to all-season tires in spring.

Do I need to replace tires if they look fine but are five years old?

Tires older than five years should be inspected by a tire professional, even if tread depth is acceptable. Rubber hardens over time, and older tires may not grip as well or handle as safely as newer tires. If your tires are approaching five years old and you drive frequently or in challenging conditions, replacement is worth considering.

What should I do with old tires after replacement?

Most tire shops will dispose of your old tires for a small fee, usually $3 to $5 per tire. Some shops include disposal in the replacement price. You can also take old tires to a recycling center or scrap metal facility. Do not leave tires on the roadside or in a landfill — improper disposal is illegal in most places.