Even the highest quality tire eventually needs to be replaced. And when that time comes, you must get the right size tire for your vehicle. Choosing the right tire size will ensure that it will correctly fit and keep you safe on the road. Keep reading to find out the answer to your question, what size tires do I need?
With so many different makes and models of vehicles on the road, how can you tell which tires are necessary for your car?
Key Takeaways
- Width, aspect ratio, and rim diameter are the most important tire measurements
- A wrong tire size on your vehicle may wear out more quickly, damage your vehicle, and put you in danger
- OE (Original Equipment) tires are the easiest option, but you can get an alternative as long as it’s the right size.
What Size Tires are Right for Me?
When you buy a vehicle, it comes with the right size tires. But once you have to replace them, you’ll need to know which ones to choose.
There are three main factors to know when choosing the right tire:
- the width,
- the aspect ration, and
- the rim diameter
You can ask an auto technician to take a look for you or look at the numbers found on your tire to help you out.
Tires have numbers on them that give you information on the three factors we just talked about. The first number will indicates tire width, the second one indicates the aspect ration, and the third one indicates what the radial construction is made from.
The final number will be the rim diameter. You can look at your current tires to find out what those numbers are and then purchase a new tire, in any brand, that has the same specifications.
What Does My Tire Size Mean?
There are several numbers that you must consider when it comes to your tires. I’ll talk about them below.
Width
The first thing we need to look at is the tire width, which you can find in the first group of three numbers on the tire. This is the measurement for your tire’s width in millimeters, from one sidewall to the other.
This means that if you see the numbers 255/60 R16, the width of the tire is 255 millimeters.
Aspect Ratio
You can find this aspect ratio by looking at the two digits that show up after the slash mark. This is going to measure the cross-section of the tire at the width.
Going back to our number of 255/60 R16 from before, we would see that in this case the 60 signifies 60% height versus the width of the tire.
The sidewall of the tire will be bigger if you have a larger aspect ratio.
Construction
As you take a look at the number on the tire, you will notice the Aspect Ratio and the Rim Diameter and right between them is a letter that tells us more about the tire’s construction.
If you have the number 255/60 R16, this R is going to stand for Radial. This means that all of the layers found in your tire are able to run across the tire, going in straight lines.
If you have a B in place of the R, this stands for Bias construction, to tell us that the layers will run in a diagonal formation across the tire instead.
Wheel Size or Rim Diameter
This number is located after the construction letter, and it’s known as the size of the wheel. This is the part that tells us more about how big the rim is for that tire and how well it will fit.
The wheel size (or rim diameter) is often measured going from one side of the wheel all the way to the other part. If you have a tire size of 255/60 R16, the 16 shows us that the wheel is 16 inches in diameter.
Load Rating/Index
Each tire has a number that states the maximum the tire is able to support when it is inflated. Of course, you need tires that can handle the weight of your vehicle.
If your tire is listed as 255/60 R16/82S, this would be 82, meaning that the load would be 1,047 pounds.
A higher tire index number shows us that the tire is going to have a bigger load carrying capacity. Make sure to get the right load rating for your vehicle.
If you install a tire with a lower load index than recommended for your vehicle, it will be too weak and won’t be able to support the car (and the passengers and other weight sources inside it).
Speed Rating
The next number that you would need to look for is the tire speed rating. This is going to indicate how fast you can go and use that tire that the tire can perform under.
Although this will indicate the max amount of speed that you can do, this number is not going to imply that you could drive safely up to that speed, especially if you are in hard road conditions. Do not go above the speed limit in the area you currently are in.
If your tire size is 255/60 R16/82S, then the S is going to be the speed indicator. In this case, you wouldn’t be able to go more than 112 miles per hour on those tires.
There are a few different speed ratings that you could encounter, so you will need to look them up based on what is found on the tire.
Why is the Tire Width Important?
Generally speaking, wider tires provide you with a better contact patch that creates better cornering and grip. However, a tire that is too wide for your vehicle will adversely affect your fuel economy and rolling resistance.
Also, they may end up rubbing the inside of the wheel wells, wearing them out too early.
Wider tires tend to be a good choice for vehicles with lots of horsepower and torque, as they provide better grip on the pavement. They lend better acceleration and less wheelspin at the same time.
Why is the Tire Height Important?
You also need to consider the height of the tire when making a purchase.
Taller wheels and tires are popular for 4WD owners who would like to improve their ground clearance, but you also don’t want to pick out a tire that is much too tall for your driving needs.
The taller the tire, the more it will affect the overall handling of the vehicle. If you go with a tire that is too high off the ground, it can lead to excessive body roll, especially if you need to move around quickly or do an emergency maneuver too.
Too-tall wheels and tires on your vehicle will also result in some rubbing on the inside of the wheel well, which can cause the tires to wear out too quickly.
What are OE Tires?
OE is going to stand for Original Equipment, which means that the tires were approved by the manufacturer of the vehicle to come standard with that vehicle.
Some vehicle manufacturers will equip their vehicles with tires that are made for them specifically for their brand.
These tires will have a special marking that says they are OE right on the sidewall.
Many companies recommend that you only use OE tires on your vehicle. These are made specifically for the vehicle.
For most vehicles, however, OE tires aren’t required. You’ll be able to purchase other tires that will work great on your vehicle, without spending as much money.
Should I Get a Tire That is Too Small for My Vehicle?
It is not a good idea for you to choose a tire that is too small for your vehicle. This can be dangerous.
When the tire is too small, it can make the vehicle drag too low to the ground. Also, you may have to worry about it not being strong enough to carry the weight of the vehicle.
Final Thoughts: What Size Tires Do I Need?
Picking the right type of tire is important if you would like to stay safe on the road and have a pleasant driving experience. Choosing the wrong tire can be a costly mistake that could put you in danger.
Look at the numbers that come on the tires to see what size of tire is right for you and if you’re uncertain about whether a tire will work well for your vehicle, you should talk to a mechanic to help make sure you are safe.