Learning how to manage tyre pressure

12 tips to better manage the pressure of your agricultural tyres

Simply by adjusting the pressure of your agricultural tyres before using your tractor, you can avoid many inconveniences. On road surfaces, under inflating your tyres will accelerate wear to the tyre rubber, while over inflating may lead to accidents while driving fast and encourage the development of ruts and soil compaction in your fields.

By checking your tyre pressure regularly, you can reduce wear, protect your soil and the quality of your crops, and therefore increase your farm’s productivity. Check out our tips on optimising the management of tyre pressure on your farm machinery: tractor, trailer, etc.

Why is tyre pressure so important?

Incorrect tyre pressure in your agricultural tyres can have a seriously negative impact on your yield and on the quality of your soil.
Luckily there are various solutions to avoid these problems and to optimise your productivity, while prolonging the lifespan of your tyres.

1. Tips for avoiding loss of yield

One of the key worries of a farmer is generally the optimisation of your yield. This depends on soil quality, how you work the soil, the inputs and weather conditions, but also the correct adjustment of the pressure of your agricultural tyres which can have an impact on your productivity.

An over inflated tyre, whatever the load it is carrying, will cause soil compaction, which hinders root development and reduces the infiltration of water to the soil. The more the soil is squashed, the higher the compaction and lower the yield per hectare.

As well as losing in productivity, using over inflated tyres can cause the formation of ruts, in particular in wet weather conditions. In this case, you will need additional work to get your field back into good condition, wasting both time and fuel.

Good to know. By reducing the pressure of your tyres, you will be contributing to protecting your soil, and therefore increasing your productivity.
However, beware of excessive underinflation which can cause your tyres to wear out more quickly if they are not designed to work at low pressure.

2. Tips for protecting your soil and your crops

Adjusting your tyre pressure is not the only means of protecting your soil.

On harvesting machines and tractors, you can also install wider farming tyres to increase the contact between the tyres and the soil and spread out the pressure over a larger surface, as long as the line spacing between your crops allows for this.

As such, the risks of compaction and rut creation will be reduced. This solution is ideal for protecting your soil and your crops.

Wider footprint = More aerated soils, less ruts
Soil protection
Lower pressure = wider footprint
= More aerated soil and less ruts

3. Tips for avoiding spinning

Spinning generally occurs when farming tyres are over inflated. This phenomenon leads to an increase in fuel consumption by up to 20%.

Excessive spinning (over 15%) will most certainly cause horizontal sliding of the upper layers of the soil and damage the soil structure.

In all cases, it is necessary to adapt your tyre pressure according to the type of soil, the weather conditions and the level of wear to the tyres, to reduce spinning:

  • On the road: a tyre, over inflated to 2 bars is ideal as the rolling resistance is reduced on tarmac.
  • In the fields: the opposite applies, as an over inflated tyre will dig into the soil more, preventing budding and increasing rolling resistance.
  • For ploughing and heavy work: optimum pressure, in other words as low as possible (0.8 bar) will provide you with greatly increased motricity with a reduced rate of spinning, savings in fuel, a reduction in wear to tyres and equipment and reduced working time.

4. Advice for reducing wear

It’s not always easy to find the ideal pressure for your agricultural tyres. While reducing pressure can be a good solution for preserving the quality of your soil, excessive under inflation can accelerate damage to the tyre’s structure. The tyre will bounce on the ground, causing:

  • Abnormal wear to the tyre lugs and shoulder.
  • Heating of the materials in the tyre structure.
  • Separation of the rubber and the elements of the casing (rayon and nylon).

There are two solutions for avoiding this:

  • On road surfaces: when using on roads the tyre has an increased resistance to the ground, increasing the tyre’s internal temperature, which can cause damage and quicker wearing out of the tread. This will have an impact on its lifespan. To reduce this wear, increase the tyre pressure slightly, especially if your machine is loaded.
  • In the fields: it is recommended to use tyres at their optimum pressure (see the manufacturer’s recommendations or contact your specialist tyre dealer), bearing in mind that they are designed to work with very low pressure with a high resistance to flexion.

5. Tips for reducing fuel consumption

Ill-adjusted pressure in your agricultural tyre will most certainly lead to increased fuel consumption. This increase will differ depending on whether you are driving on road surfaces of in fields.

  • On road surfaces: it is recommended that you increase the pressure of your agricultural tyres by up to 2 bars to save up to 30% on fuel.
  • In fields: avoid over inflated tyres as they will increase rolling resistance and dig into the soil more. A low pressure at around 0.8 bar is recommended to reduce spinning and fuel consumption.  

6. Tips for protecting your health

Has it ever occurred to you that incorrect tyre pressure has an impact on your health? Your comfort and safety also depend on the pressure of your agricultural tyres:

  • On the road: it is recommended to use a high pressure as this will make the vehicle easier to steer and will improve the breaking power of your farm machinery.
  • In the fields: a lower tyre pressure will improve shock absorption, which will reduce tiredness and back pain.

 

How to calculate the correct pressure for your agricultural tyres?

In addition to the tips provided above, there are tools which enable you to calculate the correct pressure for your agricultural tyres depending on several factors (size, load, speed, soil, etc.) to optimise their lifespan and your yield.

7. Manual calculation to determine the load on each axle

If you don’t have access to weighing equipment, you can calculate the load manually for each axle to determine the best pressure and protect your tyres.

To do this you need to know:

  • The tare weight of the farm vehicle: find this in the manufacturer’s reference documents (Front axle Weight, Rear Axle Weight). 
  • Weight of front ballast M1: or of the tool if necessary.
  • The weight of the rear mounted tool M2: manufacturer info.

Then measure the distance:

  • D1: distance between the centre of the front axle and the middle of the front ballast (M1).
  • D2: distance between the middle of the rear mounted tool (M2) and the middle of the rear axle.
  • E: distance between the middle of the rear axle and the middle of the front axle.

Once you have identified each element (some info is provided by the constructors and manufacturers), apply the following formula:

Formula for calculating the load
Formula for calculating the load

8. Use weighing tools to determine the weight carried by each axle

weighs the axle of the tractor's rear axle

Using weighing equipment will enable you to find exact measurements, in particular the actual weight carried by each axle. You just need to divide the weight by two and determine the optimal pressure for each axle.

Good to know. To weigh the front axle, check that the rear mounted tool is down. However, when weighing the rear axle, the rear mounted tool should be raised (to take into account road use).

9. Use a Smartphone app

It’s now possible to calculate the ideal pressure of your agricultural tyre using a dedicated online app. To do so, you need to have all the information relative to the weight of your farm machinery and your tools. In just a few clicks, you can get an estimation of the load and its corresponding pressure.

Firestone tyre pressure app mobile

To help you with this estimation, Bridgestone Firestone have set up an app called Tyre Pressure Bridgestone. First choose your tyre and then indicate the load to be carried by your tyres.

You will be told the optimal pressure so that you can make the necessary adjustments.

 

Solutions for always having the correct tyre pressure

Contrary to popular opinion, the pressure in your agricultural tyres is never constant. It can change from one day to the next, depending on several factors:

  • The load carried
  • External temperature
  • Level of wear to the tyre
  • The type of use: ground surface, heating…

Here are a few tips to consider for maintaining your agricultural tyres at the right pressure.

10. Develop good habits and inflate / deflate manually

To ensure that the pressure of your agricultural tyres is always adapted to your uses, you need to check it regularly.

If you don’t have access to specific tyre pressure monitoring tools (TPMS), you can inflate or deflate your tools manually depending on the load carried per type of activity.

Read the recommendations above to find the right pressure: field/road.

11. Use low pressure (VF) tyres

A technological marvel, low pressure agricultural tyres are an effective solution for reducing soil compaction. They have the advantage of spreading out the weight of the farm machinery over a wider surface. Their reinforced structure makes these VF tyres highly resistant to wear and therefore makes them last longer.

While the pressure in a standard agricultural tyre cannot go below 1.2 bar, low pressure tyres can be reduced to as low as 0.8 bar. This way, VF tyres can carry up to 40% additional load without damage to the soil: risk of creating ruts or compaction.

12. Install a central tyre inflation system

When you’re short for time, it’s not always possible to check the pressure of your farming tyres. Luckily, nowadays there are several tools on the market to help you manage this task regularly and systematically.

Among them, the central tyre inflation system is the most appropriate. An operator control panel (OCP) is installed in the tractor cabin to control the inflation system instantaneously. The system is composed of:

  • Rotary joints: they guarantee the circulation of air between the turning wheel and the stationary axle.
  • A compressor: this is the very heart of the central inflation system. It must be inflated on machinery that is not equipped with a compressed air generator.
  • An additional compressor (optional): it can be useful to reduce inflation time.
Central tyre inflation system on a 3-axle trailer
Good to know. When you are driving in the fields and on road surfaces on the same day, during harvesting for example, it is advisable to reduce the pressure in your agricultural tyres using the CTIS. This system can adjust the tyre pressure to suit your driving speed, the load you are carrying and the type of terrain.

 


The Bridgestone-agriculture.eu blog is written and administered by tractor tyre experts who are available to provide you with the advice that you need about your farming tyres. They will help you to maximise your productivity with information on all things relating to tyres: inexpensive tractor tyres - technical data for farming tyres - advice on farming tyre pressure - solution to avoid soil compaction - sprayer tyre pressure - Why and how to ballast your tractor tyres - when to use twin wheels - the mechanical causes of abnormal wear - cheap agricultural tyres - etc.

To take it further and increase your farm’s profitability, the Experts du pneu tracteur have prepared a free highly detailed eBook which explains the essential role of your agricultural tyre on your productivity.

Download eBook: Increase the profitability of your operation

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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.


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