Abstract
Abstract: Testing of Croatian producer tractor, type EUROTRAC 30 equipped with Lomabardini engine (21.0 kW rated engine power) was carried out during March and April 2007 on asphalt pathway. Prior to drawbar performance testing, engine testing via p.t.o. was done using hydraulic dynamometer. Maximal engine power of 17.3 kW was performed at engine speed of 2935 min-1 with specific fuel consumption of 312 g kWh-1. Maximal engine torque of 62.0 Nm was achieved at engine speed of 2200 min-1. At asphalt pathway, tractor in the first gear without ballast performed maximal drawbar pull of 8.60 kN, while 120 kg of added ballast improved maximal pull to 9.10 kN. Tractor without ballast in the fifth gear achieved maximal drawbar power of 16.34 kW and efficiency of 0.778 at velocity 11.10 km h-1 and wheel slip of 6.0%. Ballasted tractor also in the fifth gear performed maximal drawbar power of 16.11 kW and efficiency of 0.767 at velocity of 11.05 km h-1 and wheel slip of 5.7%.
Keywords: 4WD tractor, drawbar pull, drawbar power, fuel consumption, efficiency