USABILITY ANALYSIS OF STATIC LOAD CYCLES FOR ASSESSMENT OF TRACTOR ENGINE OPERATION ECONOMY

Summary. The paper presents results of tests on the AD3.152UR engine, carried out on a chassis dynamometer. The tests were made according to two different static load cycles, (5 and 8 phase). The operation economy of the tested engine was compared based on weighted averages of specifi c fuel consumption. It was found that in a 5-phase cycle the tested engine was characterized by lower specifi c fuel consumption and lower effective power, compared to an 8-phase cycle. It was also found that a 5-phase cycle could be representative for the province of Pomorze Zachodnie, provided the phase sequences are similar to the tractor engine time density characteristics. Key words: agricultural tractor, combustion engine, static load cycle, operation economy