Everything You Need to Know About Choosing the Right Tire Size

September 10th, 2021 by

A close up shows the tire size on a tire sidewall.

Maintaining your vehicle includes more than just changing the oil and charging the battery. One of the most important parts of maintaining a vehicle is keeping the tires in proper order, and part of that includes finding the right tires for your vehicle. Most car owners are aware that they should have certain kinds of tires for certain kinds of road conditions and seasons, such as snow tires for driving in the winter or all-terrain tires when going off-road. However, did you know that there are some important things to consider when choosing a different tire size? If you’ve been shopping around tire stores in Cincinnati to buy new tires for your vehicle, you might want to read this article first.

Different Tire Sizes for Different Vehicles

Different makes and models have different tire sizes depending on the classification of the vehicle and what the vehicle is used for. In fact, some vehicles even change classifications depending on their model year and generation, some getting bigger or smaller depending on the changes made by the company. This also changes what kind of tire size will fit on the vehicle.

For instance, sedans, trucks, SUVs, and vans have different sized chassis, and with that comes different sized wheels. Sedans obviously have smaller frames, so smaller tires are needed for their smaller wheel size. Full-size vans have larger frames, so they require tires that can handle more weight. SUVs may have different tire sizes depending on whether they’re subcompact, compact, midsize, or full-size. And trucks can also have different tire sizes depending on if you’re going with a compact, light-duty, or heavy-duty variant.

How Many Tire Sizes Are There?

Tire sizes are based on wheel sizes, and wheel sizes are based on vehicle sizes. The smallest wheel diameter, which determines the rim size, can go as low as 10-inches. On the other end of the spectrum, wheels can get quite large. For instance, some wheels have a diameter that can be as large as 30-inches.

Different tire sizes are also based on vehicle types. Smaller sedans typically have smaller wheels, and in turn, the tires are smaller for these vehicles. Some sedans that have large wheels may require special tires, however. Trucks typically have larger tire sizes in specific size ranges, especially for off-road or all-terrain purposes, same for SUVs and vans. Simply put, if you have a smaller vehicle, you will likely require a smaller tire size, and if you have a larger vehicle, you will need a larger tire size.

A close up shows the tires on the passanger side of a green truck.

How to Determine Your Vehicle’s Tire Size

Most times, you can easily determine the right tire size you’ll need for your vehicle based on the wheel size. This information is often included with the owner’s manual of the vehicle. It will give you the dimensions of the wheels and tires, so you can easily figure out what size tire you need for your ride. However, this information may not always be available, depending on the vehicle you own.

In some cases, if you bought your vehicle used and it’s been modified, or the wheels have been replaced, the tire sizes might be different than what’s in the owner’s manual. Additionally, if you purchase the vehicle specifically because it’s been modified, it may no longer have the original equipment from the manufacturer installed. This can sometimes lead to confusion regarding what tire size you may need for your vehicle.

Most times, if you have non-OEM tires on a vehicle, you can determine what tire size you need by looking at the tire wall. For nearly all modern tires, you find what is called the P-Metric system. This is a series of numbers indicating the width of the tire, as well as the aspect ratio of the tire wall and the diameter of the wheel.

Barring that, if you’re still unsure what the wheel size is for your car, truck, van, or SUV, you can easily determine the size of your vehicle’s wheel by measuring the diameter of the wheel. If you have a ruler or measuring tape, you can determine the diameter by measuring it end-to-end. Once you have the measurement, you’ll know what size tire can fit on the wheel.

Choosing The Right Tire Size For Your Vehicle

With the wheel size information in hand, it’s just a matter of finding the right kind of tire for your vehicle. If you have a truck or SUV, then you’re likely going to need a tire sized between 25 and 30 inches. This is also the standard size for most trailer tires. If you’re planning on going off-road, you want all-terrain or mud-terrain tires, and most of those will be between 30 and 35 inches. Off-road tires are larger to give the vehicle extra ground clearance and to protect the wheels with a thicker sidewall.

Most times, you can easily find the right size by outlining the make, model, and year of the vehicle. You still have to be careful because some manufacturers will make special editions or have special options that come with different size wheels and tires from the standard model. This is why it’s important sometimes to double-check and measure the wheel or tire size yourself just to be sure it matches up with the owner’s manual. Getting the measurements of the diameter and tire width will give you an idea of what size tire best suits your vehicle.

A mechanic is holding a tire at one of the most popular tires stores in Cincinnati.

Tire Size Load Capacity And Class

As mentioned, most tires will have the classification of the tire on the sidewall. This is usually indicated by a letter designation. The classes include ‘P’ for passenger vehicles, ‘T’ for a temporary or spare tire, ‘ST’ for special trailer, and ‘LT’ for a light truck. You never want to use a temporary or trailer tire on a road vehicle, and passenger tires may not be strong enough to support a fully loaded truck.

Another thing to consider is that different size tires also have different load capacities. For cars, this usually is not a major deal as most tires will have more than enough load capacity to support the average sedan. However, if you have a large SUV or truck that you use for towing or hauling, getting the right load capacity is vital. Too little load capacity, and you risk a blowout when you put your vehicle to work.

Finally, you may want to consider the speed rating of the tire. Again, this is not a common concern as most modern tires can handle any sort of common highway speeds. However, if you have a high-performance car, you will want to make sure your tires have a high enough speed rating to keep you safe. While speed ratings are classified in terms of miles per hour, you will want a tire with a higher mph rating than your actual top speed to provide you with a margin for heavy braking and acceleration.

When In Doubt…

Don’t let the sidewall references confuse you or put you off from finding the right sized tires for your vehicle. If you’ve been searching for a new set of tires from tire stores in Cincinnati, but have been coming up short, don’t hesitate to ask questions. Sometimes the tire charts can be confusing, and finding the right sized tires may seem overwhelming, but there are plenty of certified experts here at McCluskey Chevrolet who can help you identify the right size tires you need for your vehicle.