In 2016 nearly 114 thousand agricultural tyres were sold in Poland. Changing them in the tractor is a significant cost, so choosing the right tyre is important. Appropriate type of tyre allows to reduce vehicle's operating costs – for example, using radial tyres instead of diagonal tyres can reduce fuel consumption by as much as 10-15%. Much of the energy generated by burning fuel in agricultural machinery is consumed by transport on the field – it is crucial that this energy be used as efficiently as possible. Badly suited or improperly used tyres can result in loss of traction and will cause the vehicle to slide on a soft surface. The same effect has inadequate pressure in wheels – which additionally affects their faster wear.

According to studies[2], after exceeding 50% of the tyre tread wear, the greatest traction power drops are observed – this value is also considered as the limit for tyre life in agricultural machinery. Further attrition of the tread negatively affects driving economy – both on soft ground and on paved roads. Worn tyre results in an increase in slippage and unnecessary fuel consumption – it does not translate into effective field movement. Also on the asphalt – due to increased friction – lack of tread causes greater combustion.

Pressure is another important parameter in wheels that affects combustion while driving on unpaved ground. In this case, lower tyre pressure results in optimal vehicle traction and reduced slide. Radial tyres are perfectly suited for this – their construction causes them to buckle in a suitable and controlled way, thereby increasing the area of the press on the soil. Thanks to that, the surface on which the vehicle with such tyres moves is less flattened and the traction properties of the tyre increase.

“Proper tractor tyres – such as using radial tires instead of diagonal ones – will reduce fuel consumption by 3-12%, which translates into lower operating costs. Of course, the type of tyre is not everything, just as important is its proper exploitation – ie correct maintenance, optimal weight distribution or proper wheel pressure. Especially the latter parameter is often incorrectly set – it is common to use too much pressure when working in the field, and usually from 1 to 1.6 bar is enough. Tyre manufacturers in the product specification thoroughly describe the parameters of their exploitation, which take into account many factors such as the type of work, the tractor mass or its speed – therefore it is in the interest of the user to read carefully the indications and their use” – said Piotr Sarnecki, Director General of Polish Tyre Industry Association (PTIA).

The most important reasons that affect tread wear in agricultural tires are:

• incorrect toe – bad wheel geometry accelerates tyre wear, especially front ones
• lever backlash/worn steering wheel bearings – this results in incorrect gradient of the wheels against the ground
• improperly adjusted pressure – for optimum traction it should be selected to the ground type, resulting in lower fuel consumption

[2] Source: R.C. Fluck, „Energy in Agriculture”, tom 6. “Energy in Farm Production”, Elsevier, Amsterdam-London-New York-Tokyo 1992, page 174

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