The objective of this study is to determine the operating characteristics of economical PTO operation (540E) in field conditions and to make a comparison with 540 PTO operation. For this purpose three different brands of tractors (JD 5625, NH TD85, MF 3085) having similar technical properties and three PTO driven agricultural machine (single disc fertilizer spreader, turbo atomizer and rotovator. In the experiments tractor ground speed, slip values, PTO torque, PTO power, fuel consumption per time, effective field capacity and fuel consumption per field parameters were determined for two PTO operations. According to the fuel consumption data obtained, the fuel saving ratios obtained with 540E operation varied between 14.69%-34.41% To for the tractor-machine interactions used. It was determined that the motor-PTO speed ratios of the tractors were effective on fuel saving ratios. In the field experiments made at a single gear level for each tractor, the tractor ground speed values decreased by ratios varying between 12.83%-22.60% for 540E PTO operations in comparison to 540 PTO operations. This result that is caused by running both PTO operations at different motor speeds also caused a decrease in the machine's effective field capacity values calculated for 540E operation. Taking into account all the measurement parameters, it was concluded that economical PTO operation would bring certain advantages in terms of fuel consumption for many PTO driven machines and that these advantages decreased depending on the increase in the machine power requirement. According to this result, if economical PTO operation is used together with the proper gear level and ground speed selections for the tractors, it can be suggested as an important alternative to the 540 operation for machines used in this study and also for those having similar capacities and properties.