Load Range vs. Load Index: Tire Load Rating
Load Range vs. Load Index: Tire Load Rating
Take a look at any tire sidewall and you’ll see a series of numbers and letters. These letters, numbers and symbols may seem confusing, but they represent crucial information about the specifications of the tire, including speed rating, tire size, load range, and the load index of a tire.
Although load range and load index may seem a bit baffling to the average driver, the goal at Mavis Tires and Brakes is to make sure that you understand exactly what you’re putting on your car, so that you feel confident on the road.
Let’s take a deep dive into load range vs. load index, so you can make a better, more informed decision about your next set of tires from Mavis Tires and Brakes.
Why Is the Tire Load Index Important?
Every tire is engineered to safely operate within a set of limitations, including things like road conditions, speed, and load capacity. The load index indicates the maximum load capacity that a tire can safely handle when inflated to its maximum load-sustaining pressure (PSI).
Understanding the load index is important because you never want to buy tires for your vehicle
that are not designed to carry the weight of your vehicle and its contents. Exceeding the capacity of the tire can cause everything from uneven wear and tear to tire blowout and loss of control.
The tire load index is especially important if you own a light truck or large passenger vehicle that may require a tire with a higher load index when loaded down with passengers or other payloads.
How to Use the Tire Load Index Chart
The first step to understanding the load index is to understand the information on a tire’s sidewall. The number just before the letter at the very end indicates the tire load index.
It usually looks something like this: 235/55R18 90H
Once you have that, check out the load index chart and find the corresponding number. For the example above, a load index of 90 equals 1,323 pounds on the chart. This means that this single tire inflated to its maximum load-sustaining pressure can carry a maximum weight of 1,323 pounds. Multiply that number by four and you have the total amount of weight that the tires can support on a vehicle.
For reference, most passenger cars have a load index rating ranging from 70 to 124. Low tire load index numbers are typically applied to off-road vehicles, motorcycles, or other recreational type vehicles. High load index tires are usually commercial tires that are found on heavy-duty trucks or trailers that are designed to haul tons of weight.
Ply Rating and Load Range: Key Considerations
All tires are constructed of rubber and layers of durable polyester, nylon, aramid, and rayon material known as cords. Tire manufacturers layer rubber and cords together to form the modern tire and these layers are known as plies. In general, the more plies a tire has, the more durable and capable it is.
Load range is based on an older measurement technique known as ply rating. Manufacturers would count the numbers of plies, then market them accordingly. Modern tire manufacturers use plies that are stronger and more durable than ever before, so most modern tires have far fewer plies.
Today, the number of plies indicated on a load range chart is more of a measurement of strength than an exact description of the number of plies. For example, a tire may measure out to be six plies strong, but in reality, it may only have four plies because the plies are stronger.
Most passenger vehicle tires offer a four-ply design and the load range is marked as “standard load”. Light truck tires, trailer tires, and other heavy-duty tires will have more plies and can carry much more weight.
Load Carrying Capacity and Load Index: Key Considerations
Modern tire manufacturers utilize the load index to indicate the weight carrying capacity of a tire in a much more precise manner. This allows vehicle manufacturers to dial in an original equipment tire that can carry the right amount of weight without adding on extra pounds that can compromise fuel economy or performance. After all, a sports car should have a lower load requirement than a minivan or a light truck.
When purchasing new tires, be sure to purchase tires that meet the original specifications set by the original equipment manufacturer (OEM). This will ensure that your vehicle is ready for a trip, even when you have some weight on board. Consult with the experts at Mavis Tires and Brakes if you have questions or concerns about which PSI to run on your vehicle or what the best tire is for your particular vehicle and usage.
Tire Load Rating FAQs
What is the tire load index?
The tire load index is a number that represents the maximum load carrying capacity of a tire at the maximum load sustaining pressure. It’s important to note that the tire pressure placard on the door jamb indicates the recommended PSI for optimum ride, handling, and fuel economy, but not necessarily the maximum load-sustaining pressure for the tire. Maximum air pressure for any tire is located on the sidewall of the tire.
What load rating tires do I need?
Most passenger vehicles have a load index rating between 70 and 124 and the size of the tire will correspond appropriately to the load rating. Larger tires that are typically fitted to light trucks or larger SUVs will have a higher load index, while smaller tires fitted to economy cars will have a lower load rating.
If you’re towing, regularly have a payload in a truck bed, or are searching for trailer/RV tires, you’ll need to have a tire with a higher load rating that can handle the weight of what you’re carrying.
What is the difference between load index and load range?
The load index indicates the load capacity of a tire at the maximum PSI. Load range is a measure of strength based on the number of layers, or plies, in a tire. In general, the more plies, the more load capacity the tire has. Most passenger vehicle tires are four-ply designs, while commercial tires, RV tires, and trailer tires may have 8, 16, or even 24 plies.
Shop with Mavis for an Unforgettable Tire Buying Experience
Understanding the complicated specifications of a tire can be confusing, but finding the right tire for your needs is a breeze at [[mavis_brands]].
The experts at Mavis will help you find the right tire and explain everything you need to know to make an informed decision. Choose from brands you can trust, such as Goodyear, Michelin, Bridgestone, and more, all at affordable prices.
Mavis’s conveniently located shops can also help with everything from a full inspection to tire repairs and air pressure checks. Schedule an appointment to get back on the road today.
[[mavis_brands]] has great deals and is your first and last stop for all your tire needs.