Do you know how to read your wheels?

Sooner or later, you’re going to need new tires and or wheels. Do you know what size your wheels are or what tire size you need? If you do, move on, this post isn’t for you. Unless you need a refresher lol. If you don’t know, then keep reading if you want to learn more about your wheels/tires. You've probably noticed the many numbers and letters on your tire and wondered what they meant. In this post we will break it down piece by piece so by the end you will be more knowledgeable and impress the people at the tire or wheel shop next time you need to make a purchase.

Every tire will have a series of numbers and letters imprinted on it. It will look something like this “195/55/R16/87V”. Let's break it down to better understand each part of this so you can better understand your wheel and its sizes.

Starting at the beginning of the sequence, the 1st number is the width in millimeters

The next # after the slash is going to be the aspect ratio, which tells you how tall your tires profile is. It's going to be a % so if it says 55 that means the tires height is 55% of its width

Side note, if your vehicle has a lower aspect ratio, it generally will have better advantages when it comes to handling performance compared to higher aspect.

After that is the letter which represents the internal constructions that keeps your tire stable. It will either be a “R” for Radial, “D” for diagonal or “B” for Bias Ply. Most of the time you'll see “R” since it's the most common. To break it down further, the construction of it means the internal ply cords in the tire are going in a radial rotation. Occasionally you might see RF for run flat tire or ZR which means the tire has a speed rating higher than V. (We will get to speed rating soon)

Now the Big one, your rim size! That will be the # after the R or whatever ones were just listed above. For example, R16, the “16” is the size so if you need to get new wheels from us here at Santa Ana Wheel, and we ask what size is your wheel? You now know that it’s 16.

After the rim size, you're going to see the load index, that is how much weight, in pounds, the tire can support once its fully inflated. You may look and see that it says something like the above example, “87V” and think, there's no way my tires can only carry 87 lbs. when the car itself is waayyy more than that! Yea its confusing, I know lol. So, the # alone won't tell you unfortunately, it’s going to correspond with a specific load capacity from an index (will be listed below). For example, 87 can carry 1,201 lbs.

Last, we have the speed rating. It is indicated with a letter and lets you know the top speed it’s safe to drive at for a continuous time. If a tire has a higher speed rating, then it will be able to handle heat better and provide better control at higher speeds. Occasionally you’ll get tires with different speed rating so it's best to abide by the lowest one to be safe.

Below I will include the charts so you can know your load index as well as max speed based on the symbol. Hope all this helped and you’ll be better prepared moving forward when you need to purchase new tires or wheels!

Tire Size Charts

LOAD INDEX

-Heather Jarkow