By: The Working Forest Staff
Nokian Heavy Tyres, Nokia, Finland, 29 April 2020 – Released in 2019, the Nokian Ground King hybrid pattern tractor tire promises to be the first to bring new kind of efficiency to combined field and road application in agriculture. Working in collaboration with a local major agricultural contracting company Blunk GmbH, the German Kiel University put the tire through a series of tests in everyday practical work. The conclusion? The new Hybrilug™ pattern lives up to its promises.
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 tire as field and road applications are very different by nature – both still calling for great performance. Nokian Tyres has approached the versatility 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. But does it work in practice? The Kiel University Faculty of Agriculture, Department of Agricultural Engineering put the Nokian Ground King tire 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 tires. For reference, another identical Fendt was fitted with premium agricultural standard (AS) tire by another tire manufacturer. The tires 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
Efficiency in field use
The measurements in deep tillage application tests showed that compared to the reference tire, Nokian Ground King tire 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 tire profile and ground. In assessment of self-cleaning of the pattern types none of the tires 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 tire 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.
Picture 3: HybrilugTM technology combines the best features of traditional lug and block tire patterns in order to improve all-terrain mobility, great road properties and a long operating life.
Service life and fuel economy
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 tire definitely demonstrates less wear over the trial’s total operational spectrum. The lug-patterned reference tire lost more than third of its usable lug height, while the Nokian Ground King tire lost only a fifth of its lug height. This means considerably longer service life than that of a typical agricultural tire.
In fuel economy, Nokian Ground King demonstrated clear improvement. In heavy cultivation work the fuel consumption with Nokian Ground King tires was 1.5 l/h (i.e. 4%) lower than with the reference AS profile tires. 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 tires.
Effect to ergonomics and efficiency in work
Do the tires have a positive effect on the efficiency of everyday work? The test report makes it clear: “All drivers, as well as company workshop staff, evaluated Nokian Ground King definitely positively.” This is due to experienced better driving comfort, lower noise and good handling. As the contractor Blunk pointed out, “Drivers’ subjective impressions of the new tires’ ability to easily handle all jobs undertaken by the contractor was backed by everyone, leading to a more self-confident performance on customer farms.”
The tests were conducted in 2019 and demonstrated clearly that the Nokian Ground King tire lives up to its promises. What’s more, the collaborating contracting company was quite enthusiastic about the new tires, hoping for comprehensive sizes for every machine to be available soon.
“It’s nice to see that independent test results are similar to ours”, says Tero Saari, Product Manager at Nokian Tyres. “Efficient agriculture is good for everybody, so we are pleased to be the first to offer a solution to a known need.”
Sizes and availability
14 Nokian Ground King tire sizes will be available from Nokian Tyres’ dealers in 2020, starting with four sizes 650/65R42, 540/65R30, 650/65R38, 540/65R28 in April 2020.