The Case IH STX440QT Quadtrac tractor engine horsepower is 440 hp | 328.1 kW, PTO horsepower is 450.29 hp | 335.8 kW, and the drawbar horsepower is 345.68 hp | 257.8 kW.
Engine HP440 hp | 328.1 kW
PTO HP450.29 hp | 335.8 kW
Drawbar HP345.68 hp | 257.8 kW
PTO Transfer102.3%
Torque1650 lb-ft | 2237.4 Nm
Displacement912 ci | 14.9 L
Case IH STX440QT Quadtrac Horsepower Specs
Engine horsepower
440 hp | 328.1 kW
PTO horsepower tested
450.29 hp | 335.8 kW
Drawbar horsepower tested
345.68 hp | 257.8 kW
Case IH STX440QT Quadtrac Useful Horsepower Calculations
PTO-to-engine power transfer
102.3% of engine hp reaches the PTO
Drawbar-to-engine power transfer
78.6% of engine hp reaches the drawbar
Drawbar-to-PTO power ratio
76.8% drawbar hp vs PTO hp
Engine size per PTO horsepower
2 ci per PTO hp
PTO horsepower per liter
30.2 PTO hp per L
Engine size per engine horsepower
2.1 ci per engine hp
Engine horsepower per liter
29.5 engine hp per L
Torque per PTO horsepower
3.7 lb-ft per PTO hp
Rated speed per PTO horsepower
4.4 rpm per PTO hp
Case IH STX440QT Quadtrac Engine Specs
Engine type
turbocharged aftercooled diesel
Displacement
912 ci | 14.9 L
Bore and stroke
5.394×6.654 inches | 137 x 169 mm
Compression
16.5:1
Rated RPM
2000
Torque
1650 lb-ft | 2237.4 Nm
Torque RPM
1400
Case IH STX440QT Quadtrac Fuel, Cooling, Starting & Service Specs
Starter volts
12
Battery volts
12
Case IH STX440QT Quadtrac Horsepower Comparison Charts
Engine horsepower comparison
This model
440 hp
Average
210 hp
Low
120 hp
High
380 hp
PTO horsepower comparison
This model
450.3 hp
Average
175 hp
Low
100 hp
High
320 hp
Drawbar horsepower comparison
This model
345.7 hp
Average
150 hp
Low
85 hp
High
280 hp
Displacement comparison
This model
912 ci
Average
520 ci
Low
360 ci
High
750 ci
Torque comparison
This model
1,650 lb-ft
Average
700 lb-ft
Low
350 lb-ft
High
1,250 lb-ft
Rated RPM comparison
This model
2,000 rpm
Average
2,100 rpm
Low
1,600 rpm
High
2,500 rpm
Engine size per PTO HP
This model
2 ci/hp
Average
3.3 ci/hp
Low
2 ci/hp
High
5.2 ci/hp
Benchmarks use practical low, average and high ranges for the large ag tractor category. Use the operator manual and actual engine/tractor configuration before sizing implements or judging working power.
Case IH STX440QT Quadtrac Horsepower FAQ
How much horsepower does the Case IH STX440QT Quadtrac have?
The listed engine output is 440 hp, above the 210 hp benchmark average. That is a higher-power result, so ballast, tire setup and implement width matter if you want to use the full 440 hp.
How much PTO horsepower does the Case IH STX440QT Quadtrac have?
The listed PTO output is 450.3 hp, above the 175 hp benchmark average. That is the number to use for mowers, balers, augers, pumps and other PTO tools that need up to about 450.3 hp.
How much drawbar horsepower does the Case IH STX440QT Quadtrac have?
The listed drawbar output is 345.7 hp, above the 150 hp benchmark average. That makes the 345.7 hp drawbar number more useful than engine hp for tillage and heavy pulling.
How much engine power reaches the PTO on the Case IH STX440QT Quadtrac?
The PTO-to-engine transfer works out to 102.3%, from 440 engine hp to 450.3 PTO hp. That is a strong transfer figure when the two specs are from the same configuration.
How efficient is the Case IH STX440QT Quadtrac for pulling work?
The drawbar-to-engine transfer is about 78.6%, from 440 engine hp to 345.7 drawbar hp. That gives a more grounded pulling estimate than engine horsepower alone.
Is the Case IH STX440QT Quadtrac better judged by PTO hp or drawbar hp?
The drawbar output is about 76.8% of PTO output, comparing 345.7 drawbar hp with 450.3 PTO hp. That helps separate pulling ability from PTO implement ability.
How big is the Case IH STX440QT Quadtrac engine?
The engine displacement is 912 ci, above the 520 ci benchmark average. Bigger displacement can help low-rpm pull and load-holding feel.
Is the Case IH STX440QT Quadtrac engine stressed for its PTO horsepower?
The engine has about 2 cubic inches per PTO hp, using 912 ci and 450.3 PTO hp. That is a smaller-displacement, higher-output style result.
How much PTO horsepower per liter does the Case IH STX440QT Quadtrac make?
The output density is about 30.2 PTO hp per liter, using 450.3 PTO hp and 14.9 L of displacement. Higher hp/L means more output squeezed from each liter; lower hp/L usually means a more relaxed engine tune.
Official information note
Horsepower and engine specs can vary by year, market, engine option, fuel system, test standard and tractor configuration. Check the operator manual, spec plate, parts book and official caseih.com website before buying parts, sizing implements or making repair decisions.
