SUMMARY
In this study, the effects of air-conditioning system on tractor performance and specific fuel consumption were examined and evaluated by experimental data. Loading performed from tractor power take-off in periodically by electrical dynamometer. Fuel consumption were measured in air-conditioning off and air-conditioning on usage and comments were discussed according to these values. In same speed and loading, measured specific fuel consumption value when the air conditioning is on more than measured specific fuel consumption value when the air conditioning is off. Torque values were measured and fuel power and power take-off power were calculated, these values were compared, comments were discussed according to these values. In same speed and loading, measured power take-off efficiency values when the air conditioning is on less than measured power take-off efficiency values when the air conditioning is off. This change is determined respectively as average 4.37%, 4.34% and 8.63% negatively for the measured three brand tractors. As a result of all data, the positive effect of air-conditioning usage on specific fuel consumption, the negative effect of air-conditioning usage on power take-off efficiency were determined.