“…Fuel consumption rates for a single forest machine in a timber harvesting system are affected by the engine size, load factor, condition of the equipment, operator's driving skill, and environmental conditions, as well as the design of the machine [11]. According to Halilović et al [12], the following factors affect fuel consumption: external factors (climatic, field, and stand), machine factors (engine, working, and transmission part factors), technological factors (working method and work operations), and organizational factors (machine maintenance and operator education).…”