Start with the tread depth
The tread is the part of the tire that grips the road, and once it wears down, your car loses traction in rain, snow, and even on dry pavement. A simple way to check is the penny test: insert a penny into the tread groove with Lincoln's head upside down. If you can see the top of his head, the tread is below 2/32 of an inch and the tire is legally worn out in most states. For a more precise reading, use a tread depth gauge, which you can pick up at any auto parts store for a few dollars.
But tread depth alone doesn't tell the whole story. Uneven wear across the tire, more worn on one edge than the other, points to alignment or inflation problems that can shorten a tire's life. If you catch this early, you might be able to correct the underlying issue and extend the tire's service. If the wear is already severe, replacement is the only safe option. Our shop carries a tread depth gauge on every service call, so we can show you the numbers before we recommend anything.
Look for cracks, bulges, and cuts
Tires are made of rubber compounds that degrade over time, even if the tread looks fine. Sidewall cracks, sometimes called weather checking, appear as small fissures in the rubber and can deepen into dangerous failures. Bulges or blisters on the sidewall or tread are even more serious: they mean the internal belt has broken and the tire is at risk of blowing out at speed. Any cut that exposes the cords or is deeper than a quarter-inch is also a reason to replace the tire immediately.
These issues are often invisible from a quick glance, so it's worth inspecting your tires in good light, especially after hitting a pothole or curb. Run your hand along the sidewall (carefully, to avoid sharp edges) and feel for any soft spots or bulges. If you find any of these signs, do not drive on the tire, call for a mobile replacement. Our shop can come to your location, assess the damage, and swap the tire on the spot.
Know what can and cannot be repaired
Not every tire problem means replacement. Punctures in the tread area, like from a nail or screw, can often be repaired if the hole is smaller than a quarter-inch and located in the central part of the tread. However, punctures in the sidewall or shoulder are not repairable because those areas flex and the patch won't hold. Similarly, if the tire has been driven on while flat, the internal structure may be damaged even if the outside looks fine, this is a common reason a tire needs replacement rather than repair.
The decision also depends on the tire's overall condition. A tire that is already near the wear bars or has multiple punctures is not worth repairing. Industry guidelines recommend replacing tires that are older than six years, regardless of tread depth, because the rubber hardens and loses grip. When you call for a flat tire, our shop will inspect the puncture location and the tire's age and condition before deciding whether a repair is safe.
Check the age and mileage
Tires have a date code molded into the sidewall, usually a four-digit number preceded by the letters DOT. The first two digits are the week of manufacture, and the last two are the year. For example, 2319 means the tire was made in the 23rd week of 2019. Even if a tire has plenty of tread, the rubber degrades over time, and most manufacturers recommend replacement after six years from the date of manufacture, regardless of how many miles you drive.
Mileage is another factor, but it varies by tire type and driving conditions. A tire rated for 60,000 miles may wear out in 30,000 if you drive aggressively or on rough roads. Keep track of when you bought the tires and how many miles you've put on them. If you're unsure, our shop can read the DOT code for you and advise whether the tire is still within its safe service life. This is especially important if you bought a used car with unknown tire history.
When in doubt, get a professional opinion
You don't need to be a tire expert to know when something is wrong. If you notice vibrations at highway speeds, pulling to one side, or a thumping noise that changes with speed, these can all indicate tire problems. But some issues are only visible with the tire off the vehicle or on a balancer. A professional can check for internal damage, separation, and balance issues that you can't see from the outside.
If you have any doubt about a tire's condition, don't drive on it. A blowout at speed can cause a loss of control and a serious accident. Our mobile service can come to you, inspect the tire thoroughly, and tell you honestly whether it can be repaired or needs replacement. We'll show you the problem and explain the options, so you can make an informed decision before we do any work.