Load index: how many kilos can a tire support?

In tire management, you probably already know that there are some tire “rules”. One is the maximum load index.

This is a number representing the maximum weight supported by a particular tire model at the correct pressure. The number on the tire sidewall, however, is not the load weight.

For that, you need to consult the tire load index table.

How to find the weight a tire supports

All tires, on any vehicle, are manufactured with the main information on their sidewall. So when you need to know the manufacturing date, diameter, maximum speed and, of course, maximum supported weight, check the numbers and letters on each model's sidewall.

See where to find the:

Tire load index

The information usually appears in this order:

• DOT marking;
• Manufacturing date;
• Width and height;
• Radial or bias-ply;
• Diameter;
• Tire load index;
• Tire speed rating.

Therefore, to find the load limit of the fleet's tires, check the second-to-last piece of information. This is also the last number shown, since the speed rating is represented by a letter.

Tire load index table

Indices range from 80 to 199, and each corresponds to a maximum load defined by a standard. The range found on truck tires is between 140 and 165:

Truck tires usually carry two indices, such as 152/148. The first applies to a wheel mounted alone (3,550 kg) and the second to dual fitment (3,150 kg per tire), where each tire supports less because the load is distributed between the two.

For the complete table, from 80 to 199, consult Goodyear.

Want to see this in your fleet? Talk to a Prolog specialist

How to find a truck's load capacity

Even when you already know the tire limit, is this information important?

YES!

For two reasons:

1. The tire may support more weight than the vehicle;
2. The vehicle may support more weight than the tire.

You need to ensure that both vehicle and tire have compatible load limits, so that no part is damaged during transport.

In Brazil, the maximum weight supported by a truck is calculated per axle and CONTRAN (the National Traffic Council) is the main body responsible for setting these amounts.

Care beyond maximum load

For a vehicle and your fleet's tires to last longer, completing their full useful life, you need to take very good care of them. Paying attention to the maximum load index is just one of the crucial factors.

For vehicles…

You need a preventive maintenance schedule, carrying out vehicle inspections as planned.

Through these inspections, it is possible to have greater control over small tasks, such as changing the engine oil or the air conditioning filter.

You should, of course, determine the items in each inspection checklist by frequency.

For example, a daily checklist does not need to include an assessment of the condition of the passenger seat belt. However, checking headlights and fuel level is strictly necessary.

As for tires…

They should have their own schedule! The checklist provides a quick look at the tires; the inspector should record whether there is any damage visible to the naked eye.

Scheduled tire inspection, on the other hand, requires using a digital tread probe and collecting tread depth and tire pressure data.

This confirms whether the part is in good condition for use, needs a service (such as calibration or dispatch for retreading), or should even be scrapped.

You can learn even more about tires and tire management in our free e-book.

DOWNLOAD IT HERE. (in Portuguese)