Head to head · Utility

Allis Chalmers 8550 vs Allis Chalmers HD21

Allis Chalmers 8550 Tractor
Allis ChalmersModel A

Allis Chalmers 8550

Utility

power
300 hp
displacement
731 ci
Cylinders
6
Forward gears
20
Full 8550 specs
Allis Chalmers HD21 Tractor
Allis ChalmersModel B

Allis Chalmers HD21

Agricultural

power
225 hp
displacement
844 ci
Cylinders
6
Forward gears
2
Full HD21 specs
Allis ChalmersAllis Chalmers 8550
vs
Allis ChalmersAllis Chalmers HD21

How they compare

Headline specs vs. the whole Utility

n = 4,321–5,720

Engine Power

▲ 8550 higher · +75 hp (+33%)
8550300 hp
HD21225 hp
Median Utility Tractor55 hp

8550 is in the 97th percentile; HD21 is in the 95th · 5,383 models

Engine Displacement

▲ HD21 higher · +113 ci (+15%)
8550731 ci
HD21844 ci
Median Utility Tractor183 ci

8550 is in the 96th percentile; HD21 is in the 97th · 5,580 models

Cylinders

= Effectively tied
85506
HD216
Median Utility Tractor4

8550 is in the 93rd percentile; HD21 is in the 93rd · 5,720 models

Forward Gears

▲ 8550 higher · +18 (+900%)
855020
HD212
Median Utility Tractor12

8550 is in the 86th percentile; HD21 is in the 1st · 4,941 models

8550 (A)HD21 (B)Median Utility Tractor

Full comparison

Every spec, side by side

General Information

SpecAllis Chalmers 8550Allis Chalmers HD21Difference
ManufacturerAllis ChalmersAllis ChalmersSame
Model8550HD21—
CategoryUtilityAgricultural—

Engine

SpecAllis Chalmers 8550Allis Chalmers HD21Difference
ManufacturerAllis ChalmersAllis-Chalmers—
Model6120TNot recorded—
Power Output300hp225hp▲ 8550+75 hp · +33%
Rated RPM2,500RPM1,800RPM▲ 8550+700 RPM · +39%
Cylinders66Same
Displacement731ci844ci▲ HD21+113 ci · +15%
Bore5.3in5.3inSame
Stroke6.3in6.5in▲ HD21+0.2 in · +3%

Transmission

SpecAllis Chalmers 8550Allis Chalmers HD21Difference
TypePartial Power ShiftTorque Converter—

Dimensions & Weight

SpecAllis Chalmers 8550Allis Chalmers HD21Difference
Length285in198in▲ 8550+87 in · +44%
Width95.5inNot recorded—
Height139in99in▲ 8550+40 in · +40%
Operating Weight27,040lb45,500lb▲ HD21+18,460 lb · +68%

Hydraulics

SpecAllis Chalmers 8550Allis Chalmers HD21Difference
System TypeClosed CenterNot recorded—
Steering TypeHydrostatic PowerNot recorded—

Power Take-off (PTO)

SpecAllis Chalmers 8550Allis Chalmers HD21Difference
TypeIndependentNot recorded—
Speed 11,000rpmNot recorded—

Hitch & Towing

SpecAllis Chalmers 8550Allis Chalmers HD21Difference
Hitch TypeThree-Point HitchNot recorded—
Hitch CategoryIV/IIINot recorded—

Chassis & Drive

SpecAllis Chalmers 8550Allis Chalmers HD21Difference
Chassis Type4x4 Articulated 4WDNot recorded—
Drive Type4WDNot recorded—
Steering TypeHydrostatic PowerNot recorded—
Brake TypeHydraulic Wet DiscsNot recorded—

Electrical

SpecAllis Chalmers 8550Allis Chalmers HD21Difference
Starter TypeElectricElectricSame

Capacities

SpecAllis Chalmers 8550Allis Chalmers HD21Difference
Coolant18gal20gal▲ HD21+2 gal · +11%

Operator Station

SpecAllis Chalmers 8550Allis Chalmers HD21Difference
TypeAcousta Cab II with heat and air-conditioningNot recorded—

Category context

Both models against the field

Engine Power

median 55 hp
A · 97th percentile (300 hp)B · 95th percentile (225 hp)

Engine Displacement

median 183 ci
A · 96th percentile (731 ci)B · 97th percentile (844 ci)

Cylinders

median 4
A · 93rd percentile (6)B · 93rd percentile (6)

Forward Gears

median 12
A · 86th percentile (20)B · 1st percentile (2)

Operating Weight

median 5,303 lb
A · 96th percentile (27,040 lb)B · 99th percentile (45,500 lb)
A · 8550B · HD21Median Utility Tractor
Full spec pageAllis Chalmers 8550Full spec pageAllis Chalmers HD21