So you’re looking at buying new tires. Either you decided to do it because your current tires are starting to look a little old, or you’re on top of your game and know just based on when you bought them, that’s time to start shopping. Or maybe your car started vibrating manically, you brought it into the shop, and they told you it was time. How you got here doesn’t really matter, but what you do next does.
Buying a new set of tires is sort of a big deal. They’re hopefully going to last you six to ten years, and you want to make sure you’re getting exactly the right fit for your car while at the same time not getting ripped off. At Rent A Wheel, we can help with the latter no matter what your situation. But we also want to help you feel informed and prepared for what you’re looking at.
There are a lot of tires out there. A lot. Different brands, sizes, variations: “All season,” “summer,” “winter,” “mud,” if that’s your thing.
These variables are important to keep in mind when shopping for new tires, and all depend on where you live, how you drive, and how much you want to spend. But the TLI, or Tire Load Index, is the first thing you want to have in mind when approaching a purchase like this.
The Tire Load Index is a chart developed to help you figure out what kind of tires your car needs depending on how much it weighs and how much you carry. This can range depending on what kind of car you drive, such as filling up your truck bed if you have one.
The chart is a measurement of what each tire can support in weight, so when you’re looking at a typical passenger car tire, you would take that chart number, locate the weight it’s rated for, and multiply by four.
Unless you’re driving a formula one car that weighs nothing or a super truck that carries a hundred bags of concrete, you’ll generally be looking at tires in the 75-95 range. It’s pretty easy just to look up your particular vehicle’s weight, add in some wiggle room of a few hundred pounds depending on how many seats you might fill at any given time. Then divide that number by four, go to the cart and find which number on the Index gets closest to your answer.
Remember, you won’t have any issues picking tires with a Tire Load Index number above your car’s specific number. This is the amount of weight the tires canhold, so as long as they fit your car and rims, you can get the strongest tires available. But you need to get the tires that can hold at least the weight that you’ve determined.
Of course we can!
Let’s imagine you’re driving a sleek, meticulously clean 2017 3 Series, the 340i four-door sedan. The car all by itself, nothing and no one inside it weighs about 4000 pounds.
But then you put yourself and a friend in the front seat because obviously, you’re driving the car and you’re on a trip with an old friend. That’s another 400 pounds.
But you also brought along your friend’s dog, some hiking gear, and some snacks because you’re all going to hike a mountain. So that’s another 100 pounds.
But you also happen to have a side hustle as a wedding/birthday/graduation/Bar mitzvah DJ, and you have a full system in the trunk, disco lights and all. That’s another 200 pounds.
What we’re painting here is a full load capacity situation. You might not be a wedding/birthday/graduation/Bar mitzvah DJ, but maybe you have two more friends in the back seat. It is a sedan, after all. You’ve got the room.
When you’re looking at the weight capacity of tires, don’t just look up the car’s weight by itself because if you’re driving it, it’s never going to be by itself. Get it?
At Rent A Wheel, we make finding the Tire Load Index number as easy as can be. Once you have your estimated maximum weight, start looking at tires. Let’s say, for example, you’re browsing our wide selection, and you land a set of Nexen Aria AH7’s wicked-looking all-season tires that will get you going wherever, whenever, for as low as $48 a month.
Take note of the drop-down option that’s titled “Size.” You’ll see a lot of numbers and letters. Let’s use the Nexen Aria AH7s as our example tire and break these down.
All those numbers and letters on the Nexens’s look like this:
225/50R18 95T (26.9")
Width: That first number, 225, is the width measurement of the tire from sidewall to sidewall, in millimeters. The tire might bulge out slightly towards the top, but this number is important because you need your tires to fit onto your rims, obviously. So you want to make sure the width of the tire and the width of your rims match.
Aspect Ratio: No, we aren’t talking about film perspectives--but it actually sort of is the same idea. The aspect ratio is the relative amount of height the tire has to its width. So the number 50 signifies that the tire’s height is equal to 75% of its width. (That’s the height from where the sidewall begins to the tread, not from where it touches the ground to the highest point, mind you.)
Construction: This is one you’re going to mostly see the same of no matter what tire you’re looking at. It just means that the layers built inside the tire are radial, as shown by the letter R.
Wheel Diameter: Maybe you remember this one from geometry. The diameter is the measurement from one point of the tire to the other, straight across. The 18 is saying that this tire is built for a rim 18 inches in diameter. Not to be confused with the width.
Load Index: (Finally) We get to the load index at the end of this sequence. Well, almost the end. As we’ve discussed, the load index number dictates what amount of weight this tire is rated for. In this case, the Nexen tires have a Load Index Number of 95, meaning they can support 1521 pounds per tire. Multiply that by four, and you’ve got a set of wheels that can hold 6,084 pounds. Not too shabby!
Speed Rating: The second to last number is the speed rating identifier. This letter relates to another chart called the Tire Speed Rating Chart (very clever title.) At first glance, it looks like it goes from A to Z in alphabetical order but be careful because it’s not quite that simple. There are eight different “A” types, “H” comes way later than you think it would, and there is just no “O” rating. Or “Z,” actually. But each letter tells you how fast the tire is recommended to go at maximum speed. So on our shiny new Nexen Aria AH7’s, they have a Speed Rating number of T, which on the chart tells us we can safely go 118 miles per hour. According to the tires, not speed laws, which Rent A Wheel always obeys.
Height: The final number you see in the list since we’re here already is the height of the wheel. This one is pretty simple: It’s just the measurement from where the tire touches the ground to the tippy top. These Nexen wheels come in 26.9 inches as well as 27.7 inches if you’re looking for an extra inch.
After talking about so many numbers, we have something to admit- we make all of this extremely simple for you. At RentAWheel.com we’ve done the math to show you all the best possible options for your specific vehicle and narrow the list down to just the right match. So you don’t really need to know the specific Aspect Ratioor Construction type to look for. We’ll be right there to help.
By visiting our website, looking at tires, and inputting the year, make, and model of your pride and joy, we’ll crunch the numbers and show you tires that will be snugger than Cinderellas slipper.
Have custom rims? Modifications? Don’t worry about it. We’ve got an online support system to help you figure out exactly what you should be looking at. Our priority is to help you find the perfect match-up of tires and rims for a great price, so you and your car can be back on the road knowing full well that you not only look good, but you’re getting the best out of the rubber underneath you.