Nobody truly enjoys spending money on new tires. They’re expensive, wear more quickly than we’d like, and can be a real pain to determine the right kind. Those may come to mind when buying new rubber, but have you actually taken the time to understand what the sizes and markings on your tires mean?
For better or worse, we live in a world where litigation is king and where companies are careful to list every possible warning and bit of information that they can on a product. Tires are no exception, but the sizing figures you’ll find on the side of your new Michelins are a bit more complicated than just a number or letter.
The sizing information on your tires can tell you many things, not just the size. The letters and numbers tell you how fast you can drive, how heavy a load the tires can handle, and can even give you an idea of how comfortable those tires will be to live with on a daily basis. Let’s get into tire sizes and why they’re important.
Warning: The Drive’s editors are going to ask you to do some math in this post. We’re sorry.
Well, for starters, we assume you want to get the right size tire when you have to pony up the cash? Your local tire shop can look up the tires that came on your car, but what if you bought an options package with a special wheel size? What if the person that owned the car before you put on custom wheels?
A tire’s speed rating is the speed at which it can safely carry a load. Different types of tires carry different speed ratings. For instance, an S-rated tire can handle 112 mph, while a Y-rated tire can safely handle up to 186 mph.
Common Speed Ratings (miles per hour represents the maximum safe speed for each rating):
You might be asking why Z-rated tires don’t hold the title for the fastest tire. That’s because when Z-rated tires were introduced, it was common thinking that 149 mph was the fastest a tire could ever safely be rated. Now, we know better, which is why there are a total of three ratings on top of Z’s former top spot. Above Y-rated tires are (Y)-rated tires, which can travel more than 186 mph.
Let’s do this!
That’s it! You did it!
We know that you may get bored with your ride’s rubber, did you know you can size them up or down? Let’s do this.
We won’t get too deep into this topic in this post, but it’s important to understand that tire size is just one factor when it comes to picking out the right rubber for your car. Your vehicle likely left the factory with all-season tires, which are meant to work in a wide variety of temperatures and weather conditions, but not all.
Dedicated summer and winter tires are beneficial for people who live and drive in warm and cold climates, respectively. Make sure that the type of tire you pick is aligned with where you live and drive regularly.
Many of today’s wheel sizes are larger and more complex than even the most expensive and exclusive custom wheels from just ten years ago. Some automakers are moving up to 22-inches and above for SUV and pickup truck tires, which would have been unheard of outside of a few over-the-top customs debuting at SEMA.
If your vehicle is front-, rear-, or all-wheel drive, you’ll be faced with different requirements on rotating and buying new tires. Depending on which wheels are being driven on your vehicle, you may have to buy all four tires at once, or you might be able to get away with just two at a time.
People probably spend a lot less time thinking about their tires’ sidewalls now that whitewalls aren’t really a thing anymore, but they’re an important part of understanding a tire’s size. The sidewall is the vertical portion of a tire that starts where the rubber connects to the wheel and ends where the tire tread begins.
Tire treads are the part of the rubber that actually meets the road. You’ll need to understand how wide the tire treads are in order to accurately measure the tire’s size. Treads also gain importance when we’re talking about different types of tires, as the pattern and arrangement of treads vary for each specific tire.
You’ve got questions, The Drive has answers!
A: Yes! In fact, we explain how to do just that in this post. You’ll have to do some math to figure out the proper tire size to match your wheels, but it’s not that hard. Promise.
A: Does the sizing of the only part of your vehicle designed to actually touch the road matter? Let’s be realistic, here. Your tire sizes absolutely matter. You might be able to get away with a slightly different size, such as one that offers a larger sidewall, but only to a small degree. If you want or need a different size tire you’ll need to get different wheels and do some math to calculate the right size.
A: You can, but it’s not recommended. All-season tires are designed to provide good traction in a wide variety of weather and temperature conditions, not all of them, as the name would suggest. If you live in a place that sees snow on a regular basis, or where temperatures drop and stay below 40 degrees Fahrenheit, winter tires should be on your shopping list.
A: Sure, if you live in Southern California where snow and cold are rarities. Summer tires, like all-season tires, have an ideal operating temperature. In this case, the threshold is much warmer than all-seasons or winter tires.
A: If you stepped up in wheel size, we’re guessing that you stepped down in tire sidewall size to compensate for the extra wheel. This means that there’s less rubber to pad your vehicle against impacts, which means that you’re more likely to feel every small imperfection in the road.
Listen, we know how hard it can be to pick the right tire. Between the word-jumble that are tire specifications, as well as the tire manufacturer's names for tires that never just say what they are, it can be a pain and you might end up with the wrong shoes for your ride. That's why we've partnered up with our friends at Tire Rack. They'll take the headache out of tire shopping. All you have to do is click here.
We’re here to be expert guides in everything How-To related. Use us, compliment us, yell at us. Comment below and let’s talk! You can also shout at us on Twitter or Instagram, here are our profiles.
Jonathon Klein: Twitter (@jonathon.klein), Instagram (@jonathon_klein)
Tony Markovich: Twitter (@T_Marko), Instagram (@t_marko)
Chris Teague: Twitter (@TeagueDrives), Instagram (@TeagueDrives)
AstroAI Tire Pressure Gauge
TireJect On-Road Automotive Tire Sealant
Powerbuilt Unijack
Got a question? Got a pro tip? Send us a note: guidesandgear@thedrive.com
