Vredestein Agricultural tyres for tractors

Vredestein Traxion+

Description and Technical Details:

Technical information and data are available on the manufacturer‘s home page.

The sets of tyres to be tested were first of all mounted on the test vehicle. Both for the tests in the transport test and for the tests on use during fieldwork a Claas Axion 850 C-Matic with continuously variable transmission was used. The load in use in fieldwork was simulated by means of a braking tractor, here a Claas Axion 930 C-Matic, also with continuously variable transmission.

Since all the units under test were new sets of tyres these were run in prior to the start of the test using a uniform procedure with particular respect to the transport test on the road. This guaranteed equality in the surface area of the tread lugs for all the tyres.

For the field test the two tractors were connected by a steel cable with integrated traction load cell. In addition, a Peiseler wheel was attached to the drawbar of the towing tractor. This provided the actual driving speed across the ground during the test. The wheel slip was determined from the measurement of the towing tractor‘s wheel speed and the rolling circumference of the tested tyres. The fuel consumption was recorded using a volumetric measurement system on the towing vehicle. The test procedure was identical for each tyre set.

In the first sub-test, the fuel consumption was determined with a constant speed setting on the towing vehicle‘s cruise control, as well as a constant traction load from the braking vehicle. This was based on load data measured on a cultivator during standard stubble cultivation in the field.

In the second sub-test, the aim was to determine the maximum traction under real slip conditions with the prevailing ground conditions at the test location. For this purpose a constant speed was set on the towing vehicle and the traction requirement was continuously increased via the braking vehicle up to a wheel slip of 40 %.

With respect to moisture, the prevailing ground conditions at the time of the test were recorded by random sampling over the whole test field.

In the first sub-test the specific fuel consumptions shown in Figure 4 were measured with an approximately constant traction requirement of  approx. 50kN. This shows that, according to the work done under the test conditions the fuel requirement for the Vredestein tyre was slightly better in comparison to the reference products.

Based on the boundary conditions for the reference attachments, which were taken as a basis for the tractor settings, in this case a cultivator with known working width and depth, the area in hectares worked per hour was calculated. The results are shown in Figure 5.

Here also the  differences in specific fuel consumption are obvious. Thus, the Vredestein tyre carries out its work on the same area only just, but nonetheless approx. 1.2 % faster than the third placed candidate. The result was influence by the  working speeds resulting from the differences in adjusted slip conditions.

Based on the area treated per hour a comparison of the absolute fuel consumption and the fuel consumption related to a cultivated area can be undertaken. The overall result is reflected here with a slight advantage for the Vredestein tyre. Of course, in this case an economic added value is achieved only over a corresponding area or long-term observation. The results are shown in Figure 6.

The measurements of the kappa/slip ratio were made to calculate the transferable traction force as a function of slip and in relation to the total tractor weight used. This relation is shown by the kappa traction force coefficient without unit. The maximum efficiency factor would be reached when kappa = 1.

To provide a better and more detailed overview the results in Figure 7 have been shown in scaled format. For comparison it also shows which efficiency factor is apparent in defined slip conditions.

Because of this correlation between working speed and driving speed there is here also a direct correlation to area treated per hour and thus also to fuel consumption efficiency. In overall observation and under the given conditions the Traxion+ comes off better by a slight head than its competitors. In individual areas it even triumphs with the best traction force output. The transport cycles of the DLG PowerMix test  are characterised by the fact that specific fuel consumption is calculated during a combination of journeys in the full load range on hill sections and also on journeys in the partial-load range on flat sections and at standstill (traffic lights).

The overall result includes a weighting of these three components during a journey, related to a distance of 10 km with a loaded trailer. The loading here was the same for all sets of tyres. Scaling was based on the maximum PTO shaft output before the test was begun. At 40 km/h the maximum speed on flat sections was above the cruise control settings of the tractor.

The results shown in Figure 8 in this area also show a slight advantage in specific fuel consumption for the Vredestein tyre. In order to make the result a little clearer the resulting amount consumed is calculated in l/h in Figure 9. This also shows clearly that the test candidate is well able to hold its own against the reference products. Observed over the long-term it even offers potential for greater fuel savings.

Figure 10 shows the results for the comfort measurements. In order to give these a relevance to the whole test programme and also to routine use, emphasis was put on the damping behaviour of the tyres during the transport cycle on flat sections at 40 km/h. The results show that here also the Vredestein tyre achieves a level in the range of the reference products. With its 96 % natural vibration ratio it lies very close to the average.