3 ways to choose the right pressure
for your tractor tyres

Deformation in tractor tyres basically depends on two factors: the weight being hauled by the tractor, and the inflation pressure.
If your tyre has a higher pressure, it will be squeezed less but conversely will sink more into soft soil.
On the other hand, if the tyre has a low pressure, it will be squeezed more but this will increase its surface area in contact with the soil, thereby reducing soil compaction.
So how can you calculate the right pressure to get the best performance out of your tyres?

Pression des pneus de tracteursTo determine the right pressure to use for your agricultural tyres, you need to know the exact load on each axle. You will then know exactly how much weight is being placed on each tyre, and the optimal pressure to use to support this weight while ensuring minimal soil compaction.

 

1. Manually calculate the load on each axle

Manually calculate the load on each axle
Tractor tyre axle load

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:

  1. Your tractor's tare weight: read the manufacturer's information to find the front axle tare weight (FA tw) and the rear axle tare weight (RA tw).
  2. The weight of the rear-mounted tool M2 (manufacturer data)
  3. The front ballast weight M1 (or front-mounted tool, where applicable)

» You must then measure:

  1. The distance d1 between the centre-point of the front ballast weight (or centre-point of the front-mounted tool) and the centre of the front axle
  2. The distance E between the centre of the front axle and the centre of the rear axle
  3. The distance d2 between the centre of the rear axle and the centre-point of the rear-mounted tool

» You can then calculate the weight on each axle:

Calcul the weight on each axle

 

2. Use weighing equipment

Ballasting the tractorThis is certainly the most accurate technique if you own weighing equipment, because this will tell you the actual weight supported by each axle. After weighing, all you have to do is divide the weight by two to obtain the exact load on each tyre and then figure out (using the pressure equivalence table) the optimal pressure for the front and rear axles.

Remember that rear-mounted tools must be lowered when weighing the front axle and lifted when weighing the rear axle.

And if you regularly drive your tractor on roads, all you need to do is add 0.4 bar to the value in the pressure table to help prevent the rubber from wearing on the harder and more abrasive tarmac.

 

3. Use a smartphone app

As with the manual calculation method, you will need to have all the weight data for your tractor and tools before you can use an online app.

Firestone app tyre pressure calculatorThis is the quickest solution, but it will only give you an estimated load and therefore a pressure close to the optimal value.

But as we all know, pressure adjustments are usually neglected because there simply isn't enough time, so this is a quick and easy way to help maintain your productivity. This is why some manufacturers, like Bridgestone and Firestone, offer easy-to-use apps available on tablets and smartphones so that you can work out the best pressure in just a few clicks: http://agri.firestone.fr/downloads

 


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

Download eBook: Increase the profitability of your operation

The information contained in this publication is for guidance purpose only. Whilst every effort has been taken in its production, no responsibility can be accepted for any loss or damage arising from any kind of undetected technical or commercial error contained in this content. Any data supplied in this publication is subject to possible revision following the date of publication. Due to the constant advance of tyre technology, the contents of this publication are subject to change without notice.