no secret that buying tires would be much easier with a solid understanding of
tires. That's probably why you're on a page called "Tire Information."
Information that will help with your purchase includes how they're
manufactured, which are right for specific vehicles, and how to understand the
complex tire codes that are listed on the side of the tire. Simple tire information
will also help you to maintain your tires once they are on a vehicle, allowing
for optimal wear, performance, and vehicle safety.
The following information will improve your understanding
of tires and guide your purchasing decision.
Tires are made of several different components, including
the tread, sidewall, and tire plies, to name a few. The precise combination of
variations of these components allows for the construction of tires that are
particularly good in certain conditions, certain kinds of driving, and certain
kinds of vehicles.
Each tire has a tread pattern, which is the part of the
tire that comes into contact with the driving surface as the tire rolls. The
area that is actually touching the road at any given moment is known as the
contact patch. Treads are made up of tread blocks, which can vary in size,
shape, look, and function. Additionally, the tread pattern is made up of the
area known as the tread void, which consists of the grooves between the tread
blocks and allow the tread blocks to remain flexible. Tread grooves also remove
water out from under the tire as it rolls. Some tread patterns possess rain
grooves, which are often deeper than the tread void and are designed to enhance
water evacuation from between the contact patch and road surface.
Tires contain what is known as a wear bar. The wear bar serves as a built-in
warning system to alert you when the tire needs to be replaced. This small
raised feature within the tread void or groove is easy to see upon visual
The sidewall is the side of the tire that's easily seen
when a tire is mounted on a vehicle. It has a great deal of information on it
including the manufacturer's name, the size of the tire, the maximum inflation,
The tire bead is the part of the tire that holds it
securely onto the rim. It is constructed of a durable rubber compound that's reinforced
with a small steel cable. Keeping your tire properly inflated is crucial for
ensuring that the tire bead keeps a strong seal between the tire and the rim.
The tire shoulder is the area of the tire where the
sidewall and the tread meet.
Layers of various materials, including fabrics, plastics,
metals, and rubber are laid inside the tire to help it maintain its shape
throughout the wear and tear it experiences with pressure from the air inside
and the road outside. Each layer is known as a tire ply.
Most tire specifications can be found on the sidewall of
the tire. They are included in the series of letters and numbers sometimes
referred to as the tire code. The specifications included in the tire code are
the tire size, whether or not the tire has radial construction, the type of
vehicle the tire was manufactured for, and may also include the speed rating.
You'll also find inflation information on the sidewall of the tire, including
maximum PSI that a tire is capable of. Tire specifications also include the
load rating, which is important for vehicles that will be used for hauling or
towing. The optimal inflation level and load rating can be found in your
vehicle owner's manual.
When many people begin shopping for tires, they have a
certain look in mind for the type of tires they'd like to see on their vehicle
or a specific tire that they've had good experience with. While you may want a
certain look or a certain tire, you may not find one that fits your vehicle.
It's absolutely necessary to use the manufacturer-recommended tire size in
order for your vehicle to perform safely. In fact, automaker-certified
technicians like those employed by dealership won't install any tires on your
vehicle that aren't the perfect size. And these technicians know your vehicle
As mentioned before, the size of the tire is listed in the tire code. The code
can be read as follows: the first three digits are the width of the tire in
milimeters. This measurement is followed by a slash and then a two digit
number. That two digit number is the height of the sidewall as a percentage of
the tire's width. For example, if the tire code starts like this: 200/55, then
the height of the sidewall is 55% of 200, or 110 milimeters. If an
"R" appears after the sidewall height, that means the tire has radial
construction. The next two digits are the diameter of the rim the tire fits on.
The next number is the code that indicates the maximum load capacity of the tire.
Finally, if there is a letter at the end of the code, it is the tire's speed
rating. Here is an example of a tire code: