If you've ever wondered what makes one tire different from the next or needed to find your tire size, then we have good news. Class is in session. Before you shop for tires, read on to figure out what your vehicle uses and why you might want one brand and style over another.
This is Tim's Tire Center, and we'd like to welcome you to Tires 101. Today's lesson takes an inside look at the automotive tire, deconstructs the sidewall, and reviews the important elements that any dealer needs to consider when selling you a tire.
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Today, there are many tires competing for your money. We feature a good amount of tire brands ourselves. So what exactly makes one tire different from the next? Quite a few things. The first factor is what goes into the creation of your tire. In the early days, a manufacturer used a simple rubber compound to create a tire. Done and done. Today, some manufacturers use 200 or more ingredients in their tires. The exact ingredients and mixing processes remain secret and are one reason Tire X performs differently than Tire Y.
The next factor is what the tire is created to do. Today's drivers want a quiet ride, smooth handling, better cornering and stopping power. Depending on where a person lives, s/he may want a tire optimized for winter or summer driving. As you can imagine, one formula doesn't fit all. Depending on the desired features, different materials are used.
Finally and most important, it's essential to use a tire that works with your vehicle. Your automotive manufacturer has already determined the correct size, speed, and load capacity rating you need for optimal, safe performance. Whenever a member of our team helps you find a tire, these factors are considered.
Unlike that hat you bought, there is no one-size-fits-all when it comes to tires. You need to get the right size for safe handling. The footprint or contact patch, defined as the portion of your tire in contact with the road, is related to size and has an effect on your starting, steering, and stopping power. You can find the size on the sidewall.
A passenger vehicle tire might read like this: P 225/55R18 97T
225 tells you the tire width (measured from sidewall to sidewall), 55 shows you the aspect ratio (the relationship between the sidewall width and height from wheel to tread), and 18 is the wheel diameter in inches.
Low profile tires are known for having a wide but short footprint that provides drivers with more responsive steering, cornering, and braking powers compared to the high profile tires used on most passenger vehicles and light trucks. However, high profile tires are renowned for consistency in handling and for providing a smooth ride. They have a long and narrow footprint.
It's also worth keeping in mind that the footprint means nothing if you're out of usable tread. The more tread depth you have, the more traction you'll get. To get the best tread results, new research recommends installing your newest tires on the rear.
You don't have to be a racer to care about your tire's speed rating. Even if you always drive under 55 mph, it's worth knowing what the correct speed rating for your vehicle is for two reasons. The first is because the rating tells you the highest speed your tire can safely go - which is just worth knowing period. If you were to ignore this rating and drive faster than the speed rating on your tire for an extended period of time, you're gonna have a bad time; it could lead to a malfunction or blowout.
Second, it's worth knowing the speed rating since it usually corresponds to how stiff the sidewall is. The higher the speed rating, the stiffer the sidewall generally is and better performance you'll get. If you install a tire with a lower speed rating than recommended, you may encounter a "squishy" feeling as you drive.
Take a look at our sidewall example: P 225/55R18 97T
The letter at the end of tells you the speed rating. If you're still scratching your head about how a "T" can tell you anything about speed, then you need to learn the code. Letters go in alphabetical order from "A" (lowest) to "Y" (highest) and correspond with a certain maximum speed. The only exception is "H" which never got over its rebel stage and actually falls between "U" and "V" instead.
A tire with a higher speed rating will corner and stop better, but they tend to cost more, produce more noise, and wear faster as a trade off. They also might not do as well in rain and snow than tires with a lower speed rating. Below are some common speed ratings on tires:
Fun Fact: If you take a look at those numbers, you'll notice that not many of them end in 0, which would presumably be a good way to calculate speeds. 149? Really? But there's a reason for this. Speed was originally calculated in kilometers per hour. If you switch these numbers to kilometers, most ratings suddenly end in an easy to remember "0." For example, "118 mph" for us is "190 kph" and "149 mph" is "240 kph."
P 225/55R18 97T
Now that you know the letter at the end, what about the letter at the beginning? And what's with that final number before the speed rating? The first letter tells you the type of vehicle the tire was designed for. Common letters and their meanings are:
The final number on the tire (97) is the load index. In brief, it tells you how much weight the tire can safely hold. To figure out this number, an automotive manufacturer considers the weight of the vehicle plus the weight from passengers and cargo. Before you get worried that the 97 means 97 pounds and what vehicle is only 97 pounds. . .relax. The number actually stands for a different number. It's like numberception and you need to go deeper if you want know what the load capacity really is for your vehicle. In this example, 97 actually means the tire can hold 1,609 pounds.
Tires are more complicated than given credit for and they often require regular maintenance to provide you with their A-game. Regular rotation and balancing and inflation level checks will help extend the life of tires. Often, irregular tire wear and small punctures can be fixed before your tires become irreparable. Remember, your tires are the only thing seperating your vehicle from the road. There's a lot riding on your tires, so it's important to buy a tire that works with your vehicle. If you aren’t sure what you want out of your tire or need assistance with maintenance, take your vehicle to Tim's Tire Center. We'll help you out.
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