Do you know the maximum
load index for your agricultural tyre?

Your tyres' load index is extremely important in deciding which tools you can use with your tractor or how you can load your trailers. If you already know the weight of your tools and you can calculate the load transferred to the tractor axles, you can go ahead and buy the right type of tyres for the work you carry out most often.

We all have a tendency to load our trailers to maximum capacity during our daily work, to quickly calculate the load transfer based on the tool, and to not bother adjusting the tyre pressure between the road and the field because it takes up too much time.

But remember, if the pressure is not adjusted it can lead to rapid tyre wear and will cost you a lot of money, as you'd have to replace your tyres more often and the quality of your work would be affected (vibrations, slip, soil compaction), but not heeding the maximum load per tyre can lead to accidents that cost you even more dearly.

How to calculate the load on each axle by weighing

1. Weigh the front axle with the tool in its working position

   ---

2. Weigh the rear axle with the tool lifted

   ---

3. Ballast the front of the tractor to obtain a weight distribution of 35% at the front and 65% at the rear

   ---

4. Check that the weight obtained complies with the load index of your tyres (see table below)

   ---

5. Adjust the pressure based on the weight and driving speed

How to calculate the load on each axle without weighing

If you don't have any weighing equipment, you can calculate the load on each axle to make sure you're using the right pressure and that your tyres are protected.

»­To do this calculation, you will need to know:

»­You must then measure:

»­You can then calculate the weight on each axle:

A TYRE LOAD INDEX OF 171 A8 MEANS A MAXIMUM OF 6150 KG AT 40 KM/H MAX

In the table below you can find the load index that matches the marking on your tractor tyre.

This index tells you the maximum weight your tyre can bear at a given speed.

Equivalence table for weight in kg/tractor tyre load index

The tyre load index (LI) given in the table above is only valid if you stay below the speed code stated in the table below. In the photos for example, "171 A8" only applies to this agricultural tyre if you drive no faster than 40 km/h. Anything over this speed and your tyre will be overloaded, and will wear down very quickly and may even be extremely dangerous at higher speeds.

WHAT TYPE OF TYRE LETS YOU KEEP THE SAME PRESSURE AT ANY SPEED?

Agricultural tyres made using VF technology are the most efficient low-pressure model on the market, enabling you to carry heavier loads with greater resistance per tyre, increase your tractor's traction capacity, and reduce your fuel consumption.

However, the biggest selling point is their reinforced casing design, which allows them work in fields at a very low pressure (0.8 bar), where the compressed tyres distribute the weight across a greater surface area, preserving your crops and your productivity.

They require no pressure adjustments between roads and fields, and are able to withstand higher road speeds at the same pressure as used in the field, while still offering a comfortable drive.

Although they are more expensive, they have so many benefits that most farmers never go back to their previous models, and tyre manufacturers occasionally finance so you can maintain your cash flow while producing more and better.

To learn more and boost your farm's profits, Bridgestone Agriculture is offering you a free, detailed white paper that explains the essential role your agricultural tyres play in your productivity.

This information is intended only to make you aware of the technical and functional aspects of agricultural tires and their use. It does not allow you to make a judgment or a definitive conclusion on a given problem. Only your agricultural tire expert is able to make a technical assessment and take a final decision, case by case.