How to determine the tyre load index on your tractor

The tyre load index corresponds to the maximum load a tyre can support at maximum speed.The tyre load index is represented by a 3-digit number. It is closely linked to the speed index, which is represented by a letter. Example: 155 D.

The load index chart shows that a tyre with a load index of 155 can carry a maximum load of 3875 kg. To find out the maximum speed it can travel at, consult the speed rating chart below.

In most cases, the tyre's nominal load is less restrictive than the limits set by road regulations or the tractor's maximum axle load. You must therefore ensure that your load never exceeds these limits. To find out what the tractor's maximum axle load is, refer to the technical documentation for your machine.

Higher pressure means you can carry more load, but it's not always the best option. In fact, it's worth pointing out that in agriculture, high pressure in the field can be harmful to the soil. A wise choice would be to fit low-pressure tyres with MICHELIN Ultraflex technology, designed to carry the high load and limit soil compaction.

For use alternating between field and road, CTIS (Central Tyre Inflation System) is an interesting option, as it allows you to easily apply a pressure that is always adapted to your load and speed, without leaving your cab.

Let's take a MICHELIN MACHXBIB tyre size 710/70R42 173D.

For the same machine (a tractor, for example), two different tyres do not necessarily have the same tyre load index. Choosing one over the other depends on your use. If you need more load capacity, for example, you can opt for a MICHELIN Ultraflex VF tyre, which can carry more at a given pressure.*