Your vehicle’s tires keep you safe, but how do you go about keeping them safe?
There are tons of ways you can ensure the health of your tires, starting with knowing more about how they function and how to properly care for them.
Know Your Size
If you’ve had a car for any length of time, you’ve likely had to purchase tires at some point. The first thing the salesperson will ask for is either the make and model of the car or the size of tire you’re looking for.
If you don’t know, the aforementioned person used to guide you out to your vehicle to read the numbers on the side of your tire.
This practice is less common now that everything is computerized, but still happens if you need a replacement tire. Mostly now, tire centers prefer to go with manufacturer’s recommendations rather than matching what you previously had. More on that later.
For now, it’s important to understand what those numbers on the side of your tire actually mean. For example, it might read 205/65/16. The first number represents the width of the tire (in mm). So, that’s how wide it is across the face of the tire.
The second number, in this case 65, lists the depth of your tire between where it meets the rim and the edge of the tread on the face of the tire. Think of it as the side of the tire.
The third number, 16 in our example, is the diameter of the rim (in inches).
Each of these measurements serves a function and the proper sizing is essential for optimal performance.
In addition to those numbers, you might be wondering what the other markings mean.
You’ll often see the letter “R” following the second number in the size. Nearly every tire has this and it simply stands for Radial.
You may also see another letter, most commonly an H for everyday tires or a V for some vehicles. These letters are part of a rating scale. The letters are associated with the maximum speed the tire can maintain.
An H means the tire is rated for up to 130 miles per hour, while a tire with a V is rated for a maximum of 149 miles per hour. Although it’s rarely important when tire shopping, it’s fun to know for your next trivia game.
Why Tire Size Matters
In another era, car tires were nothing more than a single component of the vehicle. They were merely something that supported the vehicle and allowed it to move forward and backward.
But with huge advances in suspension, steering, speed, and other technologies, manufacturers now optimize the performance of the car by matching it with the ideal tire for the job.
Modern cars are innovative masterpieces--each piece is interconnected with the rest. Inasmuch, putting the wrong size of tire on your vehicle can cause the system to get out of whack.
The difference might be minor, like a hit on your gas mileage. Or it could lead to expensive repairs, or adjustments that wouldn’t normally be necessary.
Perhaps the most annoying repercussion of putting larger or smaller than recommended tires on your rig is that the vehicle may fail to recognize them, sending you irritating alarms and warning signals.
If you’ve been buying tires over many decades, another thing to note is that the function of cars has changed over that time. Where we used to primarily have rear-wheel drive vehicles, we now also have front-wheel drive, four-wheel drive, and all-wheel drive.
Because of the way these systems are set up, your tires need to match and be the right size.
Where to Find Your Tire Size
There are a few places you can look for your vehicle’s recommended tire size. Although you might be tempted to simply replace the size that’s already on your rig, for the reasons just covered, it’s always better to go with the manufacturer’s recommendations.
Start by opening the driver’s side door. Look at the frame around the doorway. You should see tire information near the bottom of the frame. It may also be located on the passenger side at the same location.
The sticker will not only list the recommended tire size, but also the recommended inflation amount. Keep this information in mind throughout this discussion.
If you don’t find it there, you can consult your owner’s manual or the internet. If you go looking online be very specific with the year, make, and model of your vehicle. Otherwise you may not get accurate results. If in doubt, your local tire shop can locate this information for you.
If you don’t know how old your tires are, they may be experiencing wear you can’t see. Look at those numbers along the side of your tire again. There will be an additional string of numbers that includes a four-digit number. For example, the number might read “1213”.
The first two digits represent the weeks of the year, so the twelfth week is at the end of March. The second set of numbers represents the year, in this case 2013. That information means the tires were produced in March of 2013. While they may not have gone onto a car right away, it gives you a general idea of their age.
There’s another important aspect of age to be aware of. Tires are made of several materials that break down over time. Even if you’re not using the tires and the tread looks good, you may have unseen problems due to erosion.
Check the Tread
If you look at a tire, you’ll see the raised portions with the grooves between them. These treads serve several functions and are commonly the first thing discussed when evaluating the health of the tire.
As the tire wears down, the tread thickness lessens. While it may look like you still have good tread, anything below a measurement of around 3/32 means you better start budgeting for new tires.
While the law may say you can run them to 2/32, the tire’s performance becomes less reliable and your safety may be in jeopardy. If you want to measure for yourself, there are small, easy to use tread measurers available for this very purpose.
In addition to the thickness of the tread, you need to understand the things that impact the wear of those treads. That basically means the way the treads function. In a perfect world, all tires would wear the same.
However, the reality is that the car's alignment can have a huge impact on the wear of the tire. In fact, if your car isn’t properly aligned it will cause your tires to wear unevenly and lead to premature replacement.
The pros recommend getting an alignment every time you purchase new tires.
Probably the primary cause of a poor wear pattern is failing to regularly get your tires rotated. Ideally you should rotate your tires every couple of thousand miles.
If you don’t drive very much, get them rotated one to two times per year. Think of it as an oil change. Just like old oil, those tires are aging even as they sit.
When they are in use, they’re carrying a heavier load in the front from the weight of the engine and the driver. That means they have a different work capacity than the tires in the back, leading them to wear down faster. In order to keep everything in balance, rotate them often.
Overall Tire Evaluation
In addition to monitoring the wear of the tire and the amount of tread that remains, keep an eye on the overall look of the tire.
Get down on the ground, face to face with each tire. You often can’t see damage from a standing position. Look for cracks in the grooves between the treads. Also watch for bulges anywhere on the tire. You may also see cables that are exposed or even sticking out of the tire.
If your tire is showing this level of wear, maneuver carefully to the nearest tire center and replace it. In fact, replace all four tires. This is another aspect of tire shopping that has evolved over the years. Let’s explain.
As mentioned above, cars have seen innumerable innovations over the past hundred years. Many of those changes have been seen in the drivetrain of the vehicle. Handling, speed, and performance are all affected by poor tire quality. So is the comfort of your ride, the sound of road noise, and your fuel efficiency.
With all of this at stake, having four tires of equal health is critical for the balance of all systems.
If, for example, the tread on the front two tires measures a seven and the back two tires are a three, you won’t be able to rotate them around. If you buy two new tires for the back, you’ll still be out of balance with two tires at 10 or 11 and two at seven.
It’s always best to replace all four tires at the same time.
Why Should I Maintain My Tires?
We often don’t put a lot of thought into the essential functions of tires until something goes wrong. The first reason to maintain your tires is simply one of inconvenience.
The best case scenario when your tire fails is that you’ll find yourself with a flat when leaving the house or the office. That’s bad enough, but obviously safety is a huge concern too. If your tire blows while you’re on the road, it could cause an accident.
In addition to the major problems, there are several other reasons to maintain your tires, such as the fact that it will save you money in fuel efficiency and provide a smoother ride.
Check Tire Pressure
Remember earlier when we mentioned where to find the proper tire pressure? This is an important number as you perform regular tire maintenance on your vehicle.
Note: Don’t take the psi number off the side of your tire. This is the maximum number, which means if you go above that you could impact the integrity of the tire. If the tire says psi 49 and your driver’s door jamb says a psi of 35, 35 is your number.
Think of it this way. The pressure in your tires changes while you drive, just like a bag of chips when you go over a mountain pass or a balloon when you move it from a warm area to a cold one.
If you max out your tire at 49, that doesn’t give it the room it needs to expand without causing damage.
When checking your tire pressure, use a basic tire pressure gauge. Press it straight into the air valve on the tire (after removing the cap). Read the results and add air if necessary. Allow air to release if it’s too high.
As a car owner, you should keep an emergency supply kit in your car. In addition to the basic supplies for nourishment, first aid, and warmth, make sure you have some tire supplies too. This list includes a jack, a tire compressor, and lug wrench. If you have a locking hub cap you’ll also need the release tool for that.
In addition, carry a can of Fix a Flat and a plug patch kit.
While it’s always better to patch a hole than to plug one, it’s a quick fix in the right situation. If you take a vehicle into a tire shop and offer to plug it, ask for a patch instead. The patch, if possible, is less impactful to the integrity of the tire.
If you need to plug a hole in a tire, use the tire plug kit. If there is a nail or screw in the tire, pull it out. Then use the corkscrew to create a clean hole. Put some air into the tire and quickly insert the plug using the device that looks like a large needle. Cut off the excess plug material and drive to the nearest tire center.
Note that tires cannot be patched on the side wall.
Learn more about the world of tires in our articles 4 Tips for Inflating a Wheelbarrow Tire and Upcycle a Tire to a Swing in 5 Steps.