5811F, Englisch, Mercedes-Benz Unimog U400

Daimler AG

Mercedes-Benz Unimog U 400 Fuel consumption when mowing road grass verge DLG Test Report 5811 F

Figure 1: Unimog U 400 during simulated mowing work

Brief description

As a universal implement carrier, Unimog model U 400 is frequently used

Fuel consumption for mowing road verges along Federal highways and motorways with com- July 08 when mowing bined edge strip and embankment mowing implements. road grass verge

Registering company Daimler AG TE/OMM-4 Unimog Product Management D-76742 Wörth a.R. Telephone: 07271 71737964 Telefax: 07271 71737964 E-mail: [email protected]

DLG e.V. Test Center Figure 2: Technology and Farm Inputs Unimog U 400 with edge strip and embankment mowing implement Content of the test

The fuel consumption during tractors are designated reference A U 400 with automated manual mowing work was simulated in 1 to reference 3. In this case, refer- gearbox (electronic drive control) the DLG Test Centre's Powermix ences 1 and 3 are standard tractors and hydrostatic auxiliary travel process using the dynamometer car. with an output range from 110 to drive was used for the mowing 120 kW and infinitely variable gear- work simulation. For comparison purposes, the same box (emission level TIER II), whilst measurement drives were carried reference 2 is a system tractor in out with three agricultural tractors. the output range of over 150 kW In the result tables, the comparison (emission level TIER III).

Evaluation – Short Version

Tested criterion Test result Evaluation Specific fuel consumption during simulated mowing work with reference to the reference tractors – In working range gear 6 Very good ++ – With hydrostatic gearbox in road gear 2, 100% pump slewing angle Satisfactory { – With hydrostatic gearbox in road gear 3, 70% pump slewing angle Good +

Evaluation scale: ++ / + / { / – / – – ({ = standard)

Specifications

Unimog U 400 Rated engine power* 175 kW Rated speed* 2200 1/min Emission level Euro4 Kerb weight 7090 kg Permissible gross vehicle weight 12500 kg Permissible trailed load 27500 kg Wheel base 3080 mm

* Manufacturer specifications, measurement of pto power not possible due to technical test rig limitations

DLG Test Report 5811 F 2 Measuring Method

Both PTO output and hydraulic out- Cycle with varying load for simulation of mowing work put were demanded from the Uni- 20 800 mog and the reference tractors via the Powermix module for the fuel 700 consumption measurements during simulated mowing work. The draw- 15 600 bar load was applied using the measuring vehicle. A cycle consist- 500 ing of alternating loads, whose out- 10 400 put requirements corresponded to (kW) power Hydraulic those of a combined mowing / implement (edge strip and embank- 300 ment mower) with power take-off, Pto torque (Nm) 5 200 was used for the measurement drives. In this case, the PTO output 100 is usually transformed into hydraulic Drawbar pull (kN) energy on the implement side to 0 0 drive the mulching heads, whilst the 0 100 200 300 400 500 600 vehicle's work hydraulics are used Time (s) directly to control the boom move- ments. Drawbar pull (kN) Hydraulic power (kW) Pto torque (Nm) The described cycle corresponds roughly to mowing work along an Figure 3: avenue or a Federal highway with Cycle with varying load for simulation of mowing work guardrail (posts). In this case, the work hydraulics are pressurised at each obstacle (tree, post), when the drive, falling back to the constant, approx. 110 kW can use this type booms are actuated to avoid the basic load again at the end. of combination mower. The opera- obstacles (grey curve). Whilst driv- This may, for example, be caused tional weights vary slightly in this ing past the obstacle, the blade by a slight incline or decline (blue case. To approximate the real oper- shaft output (PTO output) falls curve). The Powermix module was ating conditions, both the Unimog slightly (red curve). Whilst working attached at the rear of the reference and the tractors were ballasted up on the flat, relatively low, constant tractors, and at the front of the Uni- to their effective operational drawbar load occurs due to the mog. The run-in phase in the cycle weight. mulching heads' resistance in the was not taken into consideration in vegetation (blue curve). The draw- evaluating and calculating the mean bar load only increases during the values. In practice, both the Uni- final third of the measurement mog U 400 and tractors as of

Table 1: Gross weight of the tractors for the mower simulation Reference 1 Reference 2 Reference 3 Unimog U 400 Gross weight with ballast and Powermix module 10,330 kg 10,370 kg 9830 kg 10,325 kg

DLG Test Report 5811 F 3 Test results and individual evaluations

Mowing work simulation of the reference tractors, the PTO "hydrostatic, 100% pump slewing speed was also set to approx. angle", but lies significantly below During the simulated mowing 700 rpm, the appropriate gearbox the consumption achieved by refe- work, the Unimog was measured in setting was selected for the corres- rence tractor 2. Reference tractor 3 3 gearbox variants: ponding vehicle speed. had the lowest rated output and therefore also the lowest fuel con- – Manual gearbox, Figure 4 shows that the specific sumption. The different hourly con- working range gear 6 consumption values achieved by sumptions in the case of the Uni- the Unimog U 400 in all three gear- – Hydrostatic gearbox mog are attributable to the lower box settings are considerably lower in road gear 2, efficiency of the hydrostatic gear- than those of reference tractors 1 100% pump slewing angle box in comparison with the purely and 2. On average, they only differ mechanical travel drive (gear L6). – Hydrostatic gearbox insignificantly from the values of in road gear 3, reference tractor 3. 70% pump slewing angle Comparison of the absolute fuel The engine speed was set to a consumptions shows that the Uni- practical PTO speed of approx. mog's consumption does not 700 rpm. The mean, resulting deviate significantly from that of ve hicle speed during the cycle was refe rence tractor 1, even in the then approx. 5.3 km/h. In the case most unfavourable gearbox setting,

Reference 1 Reference 3 Unimog U 400 hydrostatic, 100% PSA*, road gear 2

Reference 2 Unimog U 400 mechanical, gear L6 Unimog U 400 hydrostatic, 70% PSA*, road gear 3

400 25

350 20 300 (kg/h)

250 15 200

10 150

100 5

50 consumption fuel hourly specific fuel consumption g/kWh

0 0 tractor tractor Figure 4: Figure 5: Mean specific fuel consumption over the cycle time Mean hourly fuel consumption over the cycle time during mowing work simulation** during mowing work simulation**

* PSA = pump slewing angle ** Powermix-simulation, mean value of cycle

DLG Test Report 5811 F 4

Summary and evaluation

In comparison with agricultural or just slightly above that of an tractors measured under the same economical tractor and significantly conditions, the mowing work simu- below that of a less economical lation in the DLG-Powermix tractor. These values are therefore revealed fuel consumption for the evaluated as very good to satisfac- Unimog U 400, which, depending tory. on the gearbox setting, lay below

Test

DLG e.V. – Author of the report Test Center Technology and Farm Inputs, Dipl.-Landw. Friedrich Uhlig Max-Eyth-Weg 1, D-64823 Groß-Umstadt

ENTAM – European Network for Testing of Agricultural Machines, was created from the merger of European testing sites. ENTAM’s objective is the Europe-wide distribution of test results for farmers, agricultural equipment dealers, and producers. More information about the Network is available at www.entam.com or by writing. E-mail Address: [email protected]

DLG e.V. – Test Center Technology and Farm Inputs

Max-Eyth-Weg 1, D-64823 Groß-Umstadt, Telephone 069 247 88-600, Fax: 069 247 88-690, E-mail: [email protected], Internet: www.dlg-test.de

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DLG Test Report 5811 F 6