Load Capacity

Is Your Tire’s Load Capacity Important?

Load capacity is the heaviest weight a tire can carry safely when it’s properly inflated. A simple concept, right? But it gets less than simple fast when you’re dealing with different categories of tires because each category showcases tire capacity in a different way.

The good news is that we make it easy for you. Each tire description on Treadworld.com shows you the load capacity per tire. Just choose the tire size and ply you want on each product page, and the load capacity for that specific tire configuration will be displayed. Dual load capacities for tires used on axles that have two tires on each side are also provided whenever relevant. Simple and fast.

Still, if you’d like to know a little bit more about tire load capacities, keep reading.

First, you may have noticed that tire sellers often use the terms load capacity, load range, ply rating and load index interchangeably. Do they all mean the same thing?

Sort of.

A tire’s load range, also known as its ply rating, is an indication of the horizontal and sidewall strength of a tire. It’s a term first used to describe how much weight bias tires could safely carry, at a time when the strength of each tire was defined in large part by the number of plies it had. The more plies, the stronger the tire. In today’s tire universe however, while the ply rating still provides an indication of load capacity, modern technology allows for more strength with fewer plies, and the load range is not strictly tied to the number of plies. Load range for specialty tires are typically identified as B, C, D, E or F. The letters position in the alphabet multiplied by two will give you the equivalent ply rating number. For example, C is the third letter in the alphabet, so 3 x 2 = 6 ply.

Load capacity is more commonly referred to as the load index. That measurement is indicated as a number and is commonly located on the sidewall listed after the tire size information. When you’re looking at load index charts, you’ll need to translate the load index into pounds of carrying capacity (see chart below). Smaller tires for wheelbarrows, riding lawn mowers, and similar start at zero (comparatively, load indexes for passenger cars and trailers extend to 110 and beyond). The higher the load index, the greater the load-carrying capacity.

Keep in Mind:
*For best results, replacement tires should equal or exceed the load carrying capacity of the original equipment tires.

*Tires that are loaded beyond their maximum allowable load capacity can build up excessive heat that may result in gradual damage, a completely flat tire or sudden destruction.

*If you do choose a tire with a lower load index than the original tire specifications, don’t forget that the tire will not have the load carrying capacity of the original.