The Nokian Ground King hybrid pattern tractor tyre could be the first to bring new kind of efficiency to combined field and road application in agriculture after being released in 2019. With that in mind, Nokian Tyres has been collaborating with an agricultural contracting company Blunk GmbH, the German Kiel University put the tyre through a series of tests in everyday practical work.
Nokian Ground King Delivers in Study
The working profile of a tractor in agricultural application has been changing. In addition to working in the fields, the volume of transport tasks and time on the road has increased significantly in recent years. This fact is shaping the criteria for an agricultural contracting tyre as field and road applications are very different by nature – both still calling for high level performance.
Nokian Tyres has approached the challenge with a new kind of hybrid pattern technology that offers the best of both worlds, combining the field-ready lug pattern with block pattern to improve on-road properties.
However the question still remained if it worked in practice? The Kiel University Faculty of Agriculture, Department of Agricultural Engineering put the Nokian Ground King tyre through its paces to find out.
For long-term performance testing, Fendt 724 Vario tractor owned by the agricultural contractor firm Blunk GmbH in Rendswühren was fitted with the pre-production version of the Nokian Ground King tractor tyres. For reference, another identical Fendt was fitted with agricultural standard (AS) tyre by another tyre manufacturer. The tyres were used in grassland operations and road transportations, while several measurements were carried out to follow the performance. The work on the fields included mowing, tedding, harvesting and tillage. The average time used in field application was 62% and on road 38% throughout the test period.
The measurements in deep tillage application tests showed that compared to the reference tyre, Nokian Ground King tyre had better power transfer to the ground with 2% less wheel slip. This improved working efficiency is due to the HybrilugTM tread pattern that gave a good interlocking grip between the tyre profile and ground.
In assessment of self-cleaning of the pattern types none of the tyres differed greatly in this performance respect under the given conditions on the moist clay soil. The difference of pattern types effect on the grass growth on the tracks done by the tractor i.e. strain effect to the field was assessed between first and second cut of grass. The greater pattern proportion of the Nokian Ground King tyre led to less strain on the soil and to more rapid grass regrowth after being driven over during the first and second cuts, leading to 29% higher yield expectations.
The test period consisted of 38% road use and 62% field use. The result of the long-time trial clearly shows that the Nokian Ground King tyre definitely demonstrates less wear over the trial’s total operational spectrum. The lug-patterned reference tyre lost more than third of its usable lug height, while the Nokian Ground King tyre lost only a fifth of its lug height. This means considerably longer service life than that of a typical agricultural tyre.
In fuel economy, Nokian Ground King demonstrated marked improvement. In heavy cultivation work the fuel consumption with Nokian Ground King tyres was 1.5 l/h (i.e. 4%) lower than with the reference AS profile tyres. The difference was still greater in transport tasks where the saving of 2.4 l/h represented more than 9% fuel savings compared with AS profile results. The combined consumption calculated through jobs carried out, measured consumption and time input, resulted in consumption being 11% less for the Nokian Ground King tyres.
