Only the right pressures

Independent tests organised by the Provana Group Innovation company have shown the link between the tyre pressures of an agricultural machinery and its operational efficiency in terms of running costs

The operational capabilities of every agricultural working site are influenced by several factors, both external and internal. When considering external factors such as the climate, the soil condition, the altitudes and others it is impossible to influence them, so it is fundamental to manage the internal factors in order to optimise the efficiency of the working site; there is the opportunity to reduce costs as well.

First of all it is necessary to perform a correct maintenance of every mechanical component during the job activity at the working site, this guarantees reliability and an optimised number of possible mechanical absorptions. The use of clean and high-quality fuels is important too along with a constant optimisation of tyre pressures with the aim of reducing the per hour consumption. This last point was considered at the beginning of February during the “Agri Day” event organised by the testing center of the Provana Group Innovation company, which premises are located in Izano, close to Cremona. This company is part of the Provana Group, a Group with an expertise in setting up the tyre sets which are equipped on tractors.

A focus on management costs

During the event the Provana Group staff talked about two different topics, the first one was related to the running costs linked to the use of tyres and to the fuel consumption, two factors which can be managed and reduced; the second one was a presentation of the various services of Provana. The target of these services is represented by manufacturers, tractor dealers, contractors and agricultural firms; the services are performed using specific devices and through the organisation of ad-hoc tests, which give the opportunity to evaluate in a both independent and objective way how the running cost of a tractor changes when taking into account tyre pressures. It is also necessary to say that when we talk about the running cost of an agricultural machinery we talk about the hourly cost based on the number of hours seen on the hour meter, so the number of effective working hours of the machinery.

It is also taken for granted that a good driving behaviour is observed at the working site. If these conditions are taken into account the running cost is determined by the hourly fuel consumption and the hourly cost of tyres. According to Provana the first parameter accounts for around 30/35%  of the total and the second only for around 4/6% of the total. As a consequence we might think that costs related to the use of tyres and their performances are less important when compared to fuel consumption, but in reality facts are different.

Savings up to 13 per cent

The device-based market test results show that rolling resistances are linked to the fuel consumption and are also related to tyre pressures. The difference between an optimised pressure and a non-optimised pressure can result in an up to 13% difference (or even more) in terms of both fuel and tyre consumption; this represents an expense or saving of thousands of euros every 1000 hours, which increases if the horsepower of the tractor is higher. If we consider soft soils it is important to set the right pressure according to, for example, tractor performance and soil preservation, whereas when we take into account hard soils and roads high pressures are mandatory in order to reduce the rolling resistance. As a consequence if tens of thousands of euros are spent when buying a tractor it is important not to save on technology costs, especially on tyre inflation systems which offer the possibility of inflating and deflating tyres. These are not yet widely available but they can guarantee interesting savings when equipped on a tractor.

In terms of tyres it is important to precise that factors such the initial cost or the brand are far less relevant when compared to others such as the tyre dimension, the tyre wear resistance, the lifespan of the carcass, and, above all, the pressures and loads management skills of the driver. These last ones are crucial because they influence the rolling circumference and the mechanical lead, a parameter that when it is not in the right percentage range causes some mechanical stress which increases fuel consumption and causes damages when considering dual traction insertion (braking).

For agro professionals, it is fundamental to equip the machinery with ad-hoc tyres for every kind of activity, the aim can be reached only with the help of technical consultants who work for well-equipped centres.

On the left: an example of the hourly costs of a 300 hp tractor every 4000 working hours when considering light and heavy duties. As can be seen the influence of fuel consumption is very important. On the right, instead, it is possible to see the hourly cost variations related to the pressure of tyres, so the ones linked to energy absorptions. The Provana Group tests show that if the worker sets the right tyre pressure according to the tractor usage there is the possibility to obtain significant savings

(translation of the article on the following website: Macchine Trattori – Link)