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Test report 7485
The approval
A test mark “DLG-APPROVED for individual criteria” is awarded for agricultural products which have successfully fulfilled a scope-reduced usability testing conducted by DLG according to independent and recognised evaluation criteria. The test is intended to highlight particular innovations and key criteria of the test object. The test may contain criteria from the DLG test scope for overall tests, or focus on other value-determining characteristics and properties of the test subject. The minimum requirements, test conditions and procedures as well as the evaluation bases of the test results will be specified in consultation with an expert group of DLG. They correspond to the recognised rules of technology, as well as scientific and agricultural knowledge and requirements. The successful testing is concluded with the publication of a test report, as well as the awarding of the test mark which is valid for five years from the date of awarding.
This testing was carried out on the agricultural tractor tires BKT AGRIMAXFACTOR 600/70 R 30 and BKT AGRIMAXFACTOR 710/70 R 42. The tires were tested against 5 reference tires, one of which was from a premium manufacturer. All tires were tested according to the DLG test module “Resources Protection”. As part of these tests, the traction and the transmitted tractive forces, the effect of the tires on the ground and the fuel consumption under real-life conditions in the field and on the road were all measured. Other criteria were not tested.
Assessment – brief summary
The agricultural tractor tire combination BKT AGRIMAXFACTOR 710/70 R 42 and BKT AGRIMAXFACTOR 600/70 R 30 achieved convincing results in the DLG test. Based on the test results, the DLG-APPROVED test mark was awarded for the “Resources Protection” testing module.
With a measured wheel load of 2,960 kg on the rear axle, the contact area of the BKT AGRIMAXFACTOR tires at a soil-friendly tire inflation pressure of 0.6 bar is 5040 cm² (or 3,906 cm² at a pressure of 1.3 bar).
At an inflation pressure of 0.6 bar, BKT AGRIMAXFACTOR tires have the second largest contact area of all tested tires and a correspondingly low tire contact area pressure of 0.43 kg/cm².
The ground pressures measured show a clear relation between the tire contact area and the depth of penetration. The BKT AGRIMAXFACTOR tires achieve the best values at all measured depths (10 cm, 20 cm and 40 cm); at a depth of 40 cm and an inflation pressure of 0.6 bar, the lowest ground pressure of 0.13 bar was measured.
The track depth of 6.5 cm measured at an inflation pressure of 0.6 bar is the second-lowest value. The BKT AGRIMAXFACTOR tire achieve an area performance of 2.6 ha/h at a speed of 10 km/h and an average tractive force of 45 kN, putting it in the mid range of the tested tires.
Fuel consumption during the field test is 1.7 % below the average (17.4 l/ha). Fuel consumption during the transport test is 0.3 % lower than the average of all the reference tires.
| DLG QUALITY PROFILE | Evaluation* |
| Soil protection | |
| Tire contact area | ■■■■■ |
| Ground pressure | ■■■■■ |
| Track depth | ■■■■■ |
| Fuel savings | |
| Field work | ■■■■■ |
| Transportation | ■■■■■ |
| Traction | |
| Area performance | ■■■■■ |
The product
Description and technical data
The following tire combinations were tested for the front and rear axles
Rear axle R: BKT AGRIMAXFACTOR 710/70 R 42
- tubeless radial tire
- tire width [mm]: 716
- total diameter: 2061
- recommended rim: DW 23 B
- alternative rim: DW 25 B
Front axle F: BKT AGRIMAXFACTOR 600/70 R 30
- tubeless radial tire
- tire width [mm]: 611
- total diameter [mm]: 1602
- recommended rim: DW 20 B
- alternative rim: DW 18 L, W 18 L
Table 2: BKT AGRIMAXFACTOR technical specifications
Tire pressure [bar] | |||||||
0,6 | 0,8 | 1,0 | 1,2 | 1,4 | 1,6 | 2,0 | |
| Travelling speed [km/h] | Front axle / Rear axle wheel load [kg] | ||||||
| 10 | 3.515 / 2.250 | 4.040 / 2.615 | 4.635 / 2.985 | 5.235 / 3.350 | 5.835 / 3.720 | 6.430 / 4.085 | 7.030 / – |
| 30 | 3.515 / 2.250 | 4.040 / 2.615 | 4.635 / 2.985 | 5.235 / 3.350 | 5.835 / 3.720 | 6.430 / 4.085 | 7.030 / – |
| 40 | 3.340 / 2.135 | 3.835 / 2.480 | 4.405 / 2.830 | 4.970 / 3.180 | 5.540 / 3.530 | 6.110 / 3875 | 6.675 / – |
| 50 | 3.210 / 2.055 | 3.690 / 2.390 | 4.235 / 2.725 | 4.780 / 3.060 | 5.325 / 3.395 | 5.870 / 3.730 | 6.420 / – |
| 65 | 3.055 / 1.955 | 3.510 / 2.275 | 4.030 / 2.595 | 4.550 / 2.915 | 5.070 / 3.235 | 5.590 / 3.550 | 6.110 / – |
Additional technical information is available on the manufacturer’s website: https://www.bkt-tires.com/gb/en/agrimaxfactor
The method
DLG test module ‘Resources Protection’
The aim of testing the agricultural tractor tires in the DLG test module “Resources Protection” is to examine the tires with regards to their effect on
the soil and on fuel consumption. For this purpose, the tires are mounted on suitable tractors and tested in two parts.
Part 1 is a field test under real-life conditions and Part 2 is a test of transport tasks on the DLG chassis dynamometer.
Part 1 – Field Test
The test runs are carried out on suitable agricultural land under comparable conditions. The test area must be sufficiently large, homogeneous and flat
and must be prepared for the tests. The soil type, texture, vegetation (if applicable), field history and test conditions (such as the weather, soil moisture and composition) are all documented. During the test, the moisture content of the soil is measured at depths of 0 to 30 cm.
The measurements are conducted with a vehicle combination consisting of 2 tractors. The first tractor is equipped with the tires to be tested
and the rear tractor serves as a braking tractor.
The tractors are connected by a sling with an integrated load cell (Figure 3). By this way, field operations are simulated and traction/slip curves are recorded at different inflation pressure values.
The set inflation pressure values are taken from the manufacturer-specific air pressure tables (Table 2). Attention is to be paid in order to not exceed maximum permissible wheel loads. Two pressures are chosen for the measurements:
- Minimum permitted tire pressure for 10 km/h (field work): 0.6 bar
- Average tire pressure for 50 km/h: 1.3 bar
To classify the measurement results, comparable tests were carried out on reference tires available on the market.
The following measurements were taken for the evaluation:
- Lead [%]
- Traction/slip curve [kN; %]
- Tire contact area [cm²]
- Ground pressure [bar]
- Track depth after passage [cm]
- Tractive power [kW]
- Area performance [ha/h]
- Fuel consumption [l/h]
The lead is calculated on the basis of the rolling circumference of the front and rear tires and the mechanical ratio of the tractor (front axle to rear axle) in all-wheel drive. There can be lead variations as to the manufacturer. The lead should be between 0.5 % and 5 %, optimally between 1.5 % and 3.5 %.
The contact area of each tire type can be made visible by dusting the tires. This way, the footprint area is measured (Figure 4). The depth of the
imprint resulting from the tire pressure can also be measured.
In the test, the ground pressure generated during a passage is measured by means of Bolling probes. The ground pressure is measured at depths of 10 cm, 20 cm and 40 cm (Figure 5). The ground pressure decreases as the depth increases (even when the wheel load remains the same) and it is mainly influenced by the tire contact area. The tire contact area changes as to the inflation pressure.
Part 2 – Transport run on the DLG chassis dynamometer
To simulate transportation tasks, test runs are performed on the DLG chassis dynamometer.
The testing process is based on the “DLG-PowerMix” test framework. The transport test consists of two different sections:
- Inclined section, which requires a high tractive force
- Flat section, which requires a relatively little tractive force
Slope levels have been previously defined according to real routes and added to the test programm.
The total towing weight (tractor and trailer) is simulated based on the performance class of the tractor and can range from 10 t to 40 t. For all tires, the pressure is set to 1.6 bar. During the comparison test, the position of the test vehicle on the chassis dynamometer is not changed. Accordingly, tire changes are done on the chassis dynamometer. Three test runs are performed; on the flat section at speeds of 40 km/h and 50 km/h considering the first run for conditioning.
During the runs the following measurements are recorded:
- Engine speed [1/min]
- Specific fuel consumption [g/kWh]
- AdBlue consumption [g/kWh]
- Speed and time required [km/h, s]
The essential and test-relevant vehicle specifications are recorded and documented.
The test results in detail
Test field
The tests were performed in March 2024 near Neumünster (Schleswig-Holstein) on a field planted with a catch crop (green rye). The type of soil is a sandy loam and the test field is largely homogeneous and even. The randomly measured moisture content during the testing period at soil depths from 0 to 30 cm is around 40 %. Therefore the test area is considered ‘relatively wet’.
Axle and tire loads, rolling circumference, lead and tire inflation pressure
The tires to be tested are fitted on a John Deere 6R 250. A Claas Xerion is used as braking tractor. The axle and tire loads are determined afterwards.
The towing tractor’s static weight distribution is 39 % on the front axle and 61 % on the rear axle.
Table 4 shows initial data and the measured lead values for the tested tires at 0.6 bar. All measured tires have a lead value between 0.5 % and 5 %. Reference tires B, C and E are in the optimal range from 1.5 % to 3.5 %. The BKT AGRIMAXFACTOR has the highest lead.
Traction/slip curve
The traction/slip curve at a tire inflation pressure of 0.6 bar shows that the tested tires transmit tractive forces of 46.8 kN to 55.1 kN with a slip
of 20 %. The BKT AGRIMAXFACTOR tires achieve a tractive force of 48.5 kN.
Even higher tractive forces can be transmitted with higher slip values. From an energetic andagricultural point of view, however, operation with a higher slip makes little sense.
At a tire inflation pressure of 1.3 bar and either a low or high slip, the transmitted tractive forces are lower. With a slip of 20 %, the tested tires transmit tractive forces from 39.1 kN to 46.8 kN. The BKT AGRIMAXFACTOR tires achieve a tractive force of 39.1 kN.
Table 3: Axle and wheel loads
| John Deere 6R 250 | |||
| Axle load [kg] | Distribution [%] | Wheel load [kg] | |
| Front axle | 3,820 | 39 | 1,910 |
| Rear axle | 5,920 | 61 | 2,960 |
| Total weight | 9,740 | ||
Table 4: Rolling circumference and lead
Rolling circumference and lead | ||||||
| BKT AGRIMAX FACTOR | Reference tire A | Reference tire B | Reference tire C | Reference tire D | Reference tire E | |
| Front axle | 600/70 R 30 | 600/70 R 30 | 600/70 R 30 | 600/70 R 30 | 600/70 R 30 | 600/70 R 30 |
| Rolling circumference [mm] | 4,765 | 4,781 | 4,749.80 | 4,791 | 4,774 | 4,809 |
| Rear axle | 710/70 R 42 | 710/70 R 42 | 710/70 R 42 | 710/70 R 42 | 710/70 R 42 | 710/70 R 42 |
| Rolling circumference [mm] | 6,198 | 6,151 | 6,197.6 | 6,164 | 6,174 | 6,202 |
| Lead with tire pressure of 0.6 bar [%] | 4.56 | 0.84 | 1.68 | 2.55 | 3.91 | 2.71 |
Tire contact area and track depth at 0.6 bar
A reduction of the tire inflation pressure from 1.3 bar to 0.6 bar increases the contact area of the tested tires by 7 % to reach 39 %. This results in a reduction of the contact area pressure in kg/cm² with the same wheel load.
In this case, the BKT AGRIMAXFACTOR tires achieve the second-lowest contact area pressure of 0.43 kg/cm².
The lower contact area pressure has an impact on the measured track depth, which is of 7.1 cm on the average. Having a value of just 6.5 cm, the track depth produced by the BKT AGRIMAXFACTOR tires is 8 % less than the average of the reference tires, and 18% less than the last-positioned competitor.
Ground pressure
At an inflation pressure of 0.6 bar, the BKT AGRIMAXFACTOR tires have the lowest measured pressure values on the Bolling probes.
Overall, there is a close correlation between the measured pressure values at a depth of 10 cm and the set tire inflation pressure. The ground pressure at a depth of 40 cm is primarily influenced by the size of the contact area (at a constant wheel load) In the case of the BKT AGRIMAXFACTOR tires, it is particularly evident that the value is significantly below the limit of 0.2 bar (-35 %) described in the literature.
Tractive power and area performance
The tractive power is calculated based on the tractive force and the travelling speed.
In this test, a tractive force of 45 kN was set to simulate a 3-m-wide soil cultivation implement. The tires can achieve different speed results depending on the traction (slip).
The average transmitted tractive power in the field test was 107.3 kW. In this case, the BKT AGRIMAXFACTOR tires correspond exactly to the average value of all tested tires here.
The area performance (ha/h) is calculated based on the width of the soil cultivation implement and the speed reached. The average for all tested tires
is 2.58 ha/h. Three of the tested tire sets are above average and two are below. The BKT AGRIMAXFACTOR tires achieve the third-highest area performance value of 2.60 ha/h.
Accordingly, the BKT AGRIMAXFACTOR tires are 0.8 % better than average and even 5.8 % better than the worst-performing competitor in the test.
Fuel consumption in the field test
High area perfomance tends to lead to low fuel consumption. The average consumption in the test at a tire inflation pressure of 0.6 bar and a braking force of 45 kN is 17.4 l/ha. Therefore, the BKT AGRIMAXFACTOR are 1.7 % above average of all tested tires.
![Tractive power [kW] and slip [%] with an tire inflation pressure of 0.6 bar and a tractive force of 45 kN](/fileadmin/_processed_/c/d/csm_7485_2312-0052_Bild13-GB_8ecb4f86b0.png)
![Consumption [l/ha] at a tire inflation pressure of 0.6 bar and a braking force of 45 kN](/fileadmin/_processed_/d/0/csm_7485_2312-0052_Bild15-GB_af8da2028c.png)
Fuel consumption during transport runs on the chassis dynamometer
The differences in fuel consumption during the transport runs are within a range of 3 % to 4 %.
During the 40 km/h variant in the transport test (DLG-PowerMix), the BKT AGRIMAXFACTOR tires have a specific fuel consumption of 367 g/kWh. During the 50 km/h variant in the transport test, the BKT AGRIMAXFACTOR tires have a specific fuel consumption of 372 g/kWh.
Similar results are found for fuel consumption per tonne per 100 kilometres (l/t · 100 km).
During the 40 km/h variant, the fuel consumption with the BKT AGRIMAXFACTOR tires is 4.06 l/t · 100 km.
During the 50 km/h variant, the fuel consumption with the BKT AGRIMAXFACTOR tires is 4.10 l/t · 100 km.
This report details the testing of the tractor tire combination BKT AGRIMAXFACTOR 710/70 R 42 and BKT AGRIMAXFACTOR 600/70 R 30 in line with the DLG Test Module “Resources Protection”. The internal tire pressure is reduced to 0.6 bar to determine the effects on resource conservation compared to an internal tire pressure of 1.3 bar.
The evaluation is done based on the measurement of the tire contact area, ground pressure, track depth, fuel consumption in the field test and transport runs on the DLG chassis dynamometer, traction/slip curve, tractive power, and area performance.
The BKT AGRIMAXFACTOR tires have achieved positive results in terms of tire contact area, ground pressure and track depth. The BKT AGRIMAXFACTOR tires have the lowest measured ground pressure compared to their competitors. As to the track depth, the BKT AGRIMAXFACTOR tires have the second-smallest value, resulting in a lower degradation of the soil area.
With regards to fuel consumption in the field test and in transport runs on the DLG chassis dynamometer, the BKT AGRIMAXFACTOR tires achieves good values. The same applies to the area performance.
The specifications and properties of the BKT AGRIMAXFACTOR are comparable to those of tires with VF (Very High Flexion) technology.
Manufacturer and applicant
Balkrishna Industries Ltd. (BKT)
Mumbai – 400013
India
Test execution
DLG TestService GmbH, Gross-Umstadt location, Germany, in cooperation with the Kiel University of Applied Sciences, Faculty of Agriculture, Dept. Agricultural Engineering
The tests are conducted on behalf of DLG e.V.
Department
Vehicle technology
DLG test framework
DLG Test Framework for Agricultural Tyres (current as 07/2023)
Test Engineer
Prof. Dr. Yves Reckleben (FH Kiel)
Martin Hanstein (DLG)*
Photos and graphics
DLG, Kiel University of Applied Sciences, Department of Agriculture, Dept. Agricultural Engineering and BKT Europe SrL
* Author
Contact us
DLG TestService GmbH - Groß-Umstadt location • Max-Eyth-Weg 1 • 64823 Groß-Umstadt • Tel: +49 69 24 788-600 • tech@DLG.org