Allis ChalmersModel A
Allis Chalmers D21 Series II
Row Crop
- power
- 121 hp
- displacement
- 426 ci
- Cylinders
- 6
- Forward gears
- 8
Head to head · Row Crop
Allis Chalmers D21 Series II vs John Deere 6620 Premium
John DeereModel B
John Deere 6620 Premium
Utility
- power
- 125 hp
- displacement
- 414 ci
- Cylinders
- 6
- Forward gears
- 24
Allis ChalmersAllis Chalmers D21 Series II
vs
John DeereJohn Deere 6620 Premium
How they compare
Headline specs vs. the whole Row Crop
Engine Power
▲ 6620 Premium higher · +4 hp (+3%)D21 Series II121 hp
6620 Premium125 hp
Median Row Crop Tractor138 hp
D21 Series II is in the 40th percentile; 6620 Premium is in the 42nd · 1,206 models
Engine Displacement
▲ D21 Series II higher · +12 ci (+3%)D21 Series II426 ci
6620 Premium414 ci
Median Row Crop Tractor391 ci
D21 Series II is in the 72nd percentile; 6620 Premium is in the 68th · 1,409 models
Cylinders
= Effectively tiedD21 Series II6
6620 Premium6
Median Row Crop Tractor6
D21 Series II is in the 50th percentile; 6620 Premium is in the 50th · 1,417 models
Forward Gears
▲ 6620 Premium higher · +16 (+200%)D21 Series II8
6620 Premium24
Median Row Crop Tractor16
D21 Series II is in the 16th percentile; 6620 Premium is in the 81st · 1,200 models
D21 Series II (A)6620 Premium (B)Median Row Crop Tractor
Full comparison
Every spec, side by side
General Information
| Spec | Allis Chalmers D21 Series II | John Deere 6620 Premium | Difference |
|---|---|---|---|
| Manufacturer | Allis Chalmers | John Deere | — |
| Model | D21 Series II | 6620 Premium | — |
| Category | Row Crop | Utility | — |
Engine
| Spec | Allis Chalmers D21 Series II | John Deere 6620 Premium | Difference |
|---|---|---|---|
| Manufacturer | Allis Chalmers | John Deere | — |
| Model | 3500 | 6068T | — |
| Power Output | 121hp | 125hp | ▲ 6620 Premium+4 hp · +3% |
| Rated RPM | 2,200RPM | 2,300RPM | ▲ 6620 Premium+100 RPM · +5% |
| Cylinders | 6 | 6 | Same |
| Displacement | 426ci | 414ci | ▲ D21 Series II+12 ci · +3% |
| Bore | 4.3in | 4.2in | ▲ D21 Series II+0.1 in · +2% |
| Stroke | 5in | 5in | Same |
Transmission
| Spec | Allis Chalmers D21 Series II | John Deere 6620 Premium | Difference |
|---|---|---|---|
| Type | Sliding gear with dry disc clutch | Partial power shift | — |
Dimensions & Weight
| Spec | Allis Chalmers D21 Series II | John Deere 6620 Premium | Difference |
|---|---|---|---|
| Length | 160in | Not recorded | — |
| Width | 91.3in | Not recorded | — |
| Height | 106in | Not recorded | — |
| Operating Weight | 9,502lb | 11,532lb | ▲ 6620 Premium+2,030 lb · +21% |
Hydraulics
| Spec | Allis Chalmers D21 Series II | John Deere 6620 Premium | Difference |
|---|---|---|---|
| System Type | Not recorded | Closed center load sensing | — |
| Steering Type | Power | Hydrostatic power | — |
Power Take-off (PTO)
| Spec | Allis Chalmers D21 Series II | John Deere 6620 Premium | Difference |
|---|---|---|---|
| Type | Independent | Not recorded | — |
| Speed 1 | 1,000rpm | Not recorded | — |
Hitch & Towing
| Spec | Allis Chalmers D21 Series II | John Deere 6620 Premium | Difference |
|---|---|---|---|
| Hitch Type | Three-Point Hitch | Rear Type II/IIIN | — |
| Hitch Category | III/II | Not recorded | — |
| Hitch Position | Rear | Rear | Same |
| Hitch Capacity | Not recorded | 18,740lb | — |
Chassis & Drive
| Spec | Allis Chalmers D21 Series II | John Deere 6620 Premium | Difference |
|---|---|---|---|
| Chassis Type | 4x2 2WD | 4x4 MFWD 4WD | — |
| Drive Type | 2WD | 4WD | — |
| Steering Type | Power | Hydrostatic power | — |
| Brake Type | Band actuated disc | Not recorded | — |
Electrical
| Spec | Allis Chalmers D21 Series II | John Deere 6620 Premium | Difference |
|---|---|---|---|
| Starter Type | Electric | Electric | Same |
Capacities
| Spec | Allis Chalmers D21 Series II | John Deere 6620 Premium | Difference |
|---|---|---|---|
| Coolant | 7.8gal | Not recorded | — |
Operator Station
| Spec | Allis Chalmers D21 Series II | John Deere 6620 Premium | Difference |
|---|---|---|---|
| Type | Open | Not recorded | — |
Category context
Both models against the field
Engine Power
median 138 hpA · 40th percentile (121 hp)B · 42nd percentile (125 hp)
Engine Displacement
median 391 ciA · 72nd percentile (426 ci)B · 68th percentile (414 ci)
Cylinders
median 6A · 50th percentile (6)B · 50th percentile (6)
Forward Gears
median 16A · 16th percentile (8)B · 81st percentile (24)
Operating Weight
median 12,307 lbA · 28th percentile (9,502 lb)B · 44th percentile (11,532 lb)
A · D21 Series IIB · 6620 PremiumMedian Row Crop Tractor