AGCO Corporation MT645

Last Updated: July 2024

Overview

The Challenger MT645 is a powerful row-crop tractor manufactured by AGCO Corporation. It features a Sisu/Valmet Diesel engine with 6 vertical cylinders, turbocharged and aftercooled, delivering a displacement of 449 cu in (7365 ml). The engine has a bore of 4.251 inches (108.0 mm) and a stroke of 5.278 inches (134.0 mm), operating at a rated 2200 RPM. The transmission is a selective gear fixed ratio with full range operator controlled powershift, offering 18 forward and 6 reverse gears. The tractor has an unladen mass of 19020 lb (8627 kg) and is equipped with rear tires (Two 18.4R42; **;22(150)) and front tires (Two 14.9R30; ***;24(165)). It features a power steering system (hydrostatic), and the hydraulic system is a closed center pressure flow compensated (PFC) system with additional details on performance with or without the high flow option. The tractor also has a Category III rear hitch, and the PTO delivers 181.26 HP (135.16 kW) at 2200 rpm and 183.87 HP (137.11 kW) at 2091 rpm, with corresponding fuel consumption rates. The drawbar performance is outlined by power vs fuel consumption in various conditions.

Key Specifications

Category: Row Crop

Transmission: Selective gear fixed ratio with full range operator controlled powershift

Operating Weight: 19020

Fuel Type: Diesel

Technical Specifications

Engine

Manufacturer: Sisu/Valmet Diesel
Model: -
Cooling Type: Liquid-Cooled
Cylinder Orientation: Vertical
Valve Configuration: -
Fuel Type: Diesel
Induction Type: Turbocharged, Aftercooled (Turbocharger and intercooler)
Cylinders: 6
Displacement (ci): 449 cu in (7365 ml)
Bore (in): 4.251 inches (108.0 mm)
Stroke (in): 5.278 inches (134.0 mm)
Rated RPM: 2200
Power Output (hp): -

Transmission

Type: Selective gear fixed ratio with full range operator controlled powershift
Forward Gears: 18
Reverse Gears: 6
Total Gears: -

Dimensions

Length (in): 203
Width (in): 98.2
Height (in): 121
Operating Weight (lb): 19020

Power Take-Off (PTO)

PTO Type: -
PTO Speed 1 (rpm): -
PTO Speed 2 (rpm): -
PTO Speed 3 (rpm): -

Miscellaneous

Chassis: 4x4 MFWD 4WD
Drive Type: -
Steering Type: Power Steering (Hydrostatic)
Coolant Capacity (qts): -
Front Tire Diameter (in): -
Front Tire Width (in): -
Rear Tire Diameter (in): -
Rear Tire Width (in): -
Front/Rear Rim Diameter (in): -
Tire Type: Rear tires: Two 18.4R42; **;22(150), Front tires: Two 14.9R30; ***;24(165)
Manufacture - End Year: -
Hitch Type: -
Hitch Category: III
Hitch Position: Rear
Hitch Capacity (lb): -
Operator Station Type: Cab
Starter Type: Electric, 12 Volts
Brake Type: -
Hydraulic System Type: Closed Center Pressure Flow Compensated (PFC)

Test Results

Nebraska Tractor Test Laboratory - Test Date: September 19-26, 2000

Maximum Power and Fuel Consumption

Rated Engine Speed (PTO speed—1052 rpm): 181.26 HP (135.16 kW)
Fuel Consumption: 11.29 Gal/hr (42.73 l/h)
Fuel Efficiency: 0.438 lb/hp.hr (0.266 kg/kW.h) with 16.06 Hp.hr/gal (3.16 kW.h/l)
Standard Power Take-off Speed (1000 rpm): 183.87 HP (137.11 kW)
Fuel Consumption: 10.95 Gal/hr (41.44 l/h)
Fuel Efficiency: 0.418 lb/hp.hr (0.255 kg/kW.h) with 16.80 Hp.hr/gal (3.31 kW.h/l)
Maximum Power (2 Hours): 184.49 HP (137.57 kW)
Fuel Consumption: 10.60 Gal/hr (40.14 l/h)
Fuel Efficiency: 0.404 lb/hp.hr (0.246 kg/kW.h) with 17.40 Hp.hr/gal (3.43 kW.h/l)

Torque and Engine Performance

Maximum Torque: 589 lb.-ft. (799 Nm) at 1300 rpm
Torque Rise: 36.1% with a torque rise at 1801 engine rpm of 21%

Drawbar Performance

Dynamic Drawbar Power: Results not explicitly detailed in the provided text.
Fuel Consumption in Varying Conditions:
At 181.26 HP (135.16 kW): 11.29 Gal/hr (42.73 l/h)
At 158.24 HP (118.00 kW): 10.20 Gal/hr (38.62 l/h)
At 119.33 HP (88.99 kW): 8.41 Gal/hr (31.83 l/h)
At 80.06 HP (59.70 kW): 6.53 Gal/hr (24.72 l/h)
At 40.54 HP (30.23 kW): 4.78 Gal/hr (18.10 l/h)

Hydraulic Performance

Maximum Force Exerted (Through Whole Range): 19710 lbs (87.7 kN)
Pump Delivery Rate at Minimum Pressure and Rated Engine Speed: 29.5 GPM (111.7 l/min) without high flow, 39.3 GPM (148.8 l/min) with high flow option
Hydraulic Power: 39.9 HP (29.7 kW) without high flow, 52.2 HP (38.9 kW) with high flow option

Overall Efficiency

Fuel Efficiency at Standard PTO Speed (1000 rpm): 16.80 Hp.hr/gal (3.31 kW.h/l)
Fuel Consumption: 10.95 Gal/hr (41.44 l/h) at 2091 rpm

Nebraska Tractor Test Lab, "Tractor Test 1782C: Challenger MT645" (2003). Nebraska Tractor Tests. 2292. https:/ /digitalcommons.unl.edu/tractormuseumlit/2292