ENERGY EFFICIENCY AND ENERGY SECURITY ARE OF PARAMOUNT IMPORTANCE AS PRODUCTION AGRICULTURE CONTINUES ITS PURSUIT TO PROVIDE FOOD FIBER AND FUEL FOR APPROXIMATELY 10 BILLION PEOPLE BY THE YEAR 2050. EQUIPMENT MANUFACTURERS ARE DEVELOPING NEW TRACTOR TECHNOLOGIES FOR INCREASED FUEL EFFICIENCY AND REDUCED NEGATIVE ENVIRONMENTAL IMPACTS. HOWEVER CURRENT AGRICULTURAL TRACTOR TESTING FOCUSES PRIMARILY ON CHARACTERIZING MAXIMUM PERFORMANCE WHEN FOCUS SHOULD BE ON MEASURING FUEL EFFICIENCY FOR LOAD CASES REPRESENTING TYPICAL IN-FIELD AGRICULTURAL OPERATIONS. RESULTS FROM A MORE ADVANCED TEST PROCEDURE INVOLVING LOAD CASES FROM ACTUAL FIELD OPERATIONS WOULD ALLOW PRODUCERS TO MAKE EFFECTIVE TRACTOR PURCHASE DECISIONS TO BETTER MATCH THEIR IMPLEMENTS TO TRACTORS FOR OPTIMAL POWER USE. THE GOAL OF THIS PROJECT IS TO DEVELOP LOAD CASES WITH THE DATA COLLECTED FROM FIELD OPERATIONS IN SUPPORT OF ADVANCED TRACTOR TESTING PROCEDURES IN MIXED-MODE POWER STATES. TO ACCOMPLISH OUR PROJECT GOAL OUR SPECIFIC OBJECTIVES ARE TO: 1) IDENTIFY ISOBUS/CAN MESSAGE SIGNALS CORRESPONDING TO DRAWBAR PTO AND HYDRAULIC POWER OF THE TRACTOR UNDER TEST AND CORRELATE THEM WITH THE EQUIVALENT DATA OBTAINED FROM NTTL'S EQUIPMENT INSTRUMENTATION TO DETERMINE THE FEASIBILITY OF USING ISOBUS/CAN MESSAGE SIGNALS IN LIEU OF PHYSICAL SENSOR DATA 2) COLLECT ISOBUS/CAN DATA AND PHYSICAL SENSOR DATA FROM THE INSTRUMENTATION OF TRACTOR UNDER TEST DURING ROW CROP TRACTOR OPERATIONS OVER THREE SEASONS TO QUANTIFY AND CHARACTERIZE DRAWBAR PTO AND HYDRAULIC POWER FLOWS IN FIELD CONDITIONS AND 3) GENERATE LOAD PROFILES OF IN-FIELD OPERATIONS TO PRODUCE LOAD CASES WHICH WILL BE USED AS INPUTS FOR ADVANCED MIX-MODE POWER TESTING EFFORTS.