Allis ChalmersModel A
Allis Chalmers HD20
Industrial
- power
- Not recorded
- displacement
- 660 ci
- Cylinders
- 6
- Forward gears
- 2
Head to head · Industrial
Allis Chalmers HD20 vs Caterpillar D6D SA Special Application
Image not recorded
CaterpillarModel B
Caterpillar D6D SA Special Application
Specialized
- power
- Not recorded
- displacement
- 638 ci
- Cylinders
- 6
- Forward gears
- 6
Allis ChalmersAllis Chalmers HD20
vs
CaterpillarCaterpillar D6D SA Special Application
How they compare
Headline specs vs. the whole Industrial
Engine Displacement
▲ HD20 higher · +22 ci (+3%)HD20660 ci
D6D SA Special Application638 ci
Median Industrial Tractor284 ci
HD20 is in the 76th percentile; D6D SA Special Application is in the 75th · 53 models
Cylinders
= Effectively tiedHD206
D6D SA Special Application6
Median Industrial Tractor4
HD20 is in the 88th percentile; D6D SA Special Application is in the 88th · 55 models
Forward Gears
▲ D6D SA Special Application higher · +4 (+200%)HD202
D6D SA Special Application6
Median Industrial Tractor5
HD20 is in the 1st percentile; D6D SA Special Application is in the 65th · 43 models
Operating Weight
▲ HD20 higher · +12,000 lb (+41%)HD2041,000 lb
D6D SA Special Application29,000 lb
Median Industrial Tractor9,127 lb
HD20 is in the 97th percentile; D6D SA Special Application is in the 88th · 49 models
HD20 (A)D6D SA Special Application (B)Median Industrial Tractor
Full comparison
Every spec, side by side
General Information
| Spec | Allis Chalmers HD20 | Caterpillar D6D SA Special Application | Difference |
|---|---|---|---|
| Manufacturer | Allis Chalmers | Caterpillar | — |
| Model | HD20 | D6D SA Special Application | — |
| Category | Industrial | Specialized | — |
Engine
| Spec | Allis Chalmers HD20 | Caterpillar D6D SA Special Application | Difference |
|---|---|---|---|
| Manufacturer | General Motors | Caterpillar | — |
| Model | Not recorded | 3306 | — |
| Rated RPM | 1,700RPM | 2,000RPM | ▲ D6D SA Special Application+300 RPM · +18% |
| Cylinders | 6 | 6 | Same |
| Displacement | 660ci | 638ci | ▲ HD20+22 ci · +3% |
| Bore | 5in | 4.8in | ▲ HD20+0.2 in · +4% |
| Stroke | 5.6in | 6in | ▲ D6D SA Special Application+0.4 in · +7% |
Transmission
| Spec | Allis Chalmers HD20 | Caterpillar D6D SA Special Application | Difference |
|---|---|---|---|
| Type | Torque converter | Gear | — |
Dimensions & Weight
| Spec | Allis Chalmers HD20 | Caterpillar D6D SA Special Application | Difference |
|---|---|---|---|
| Length | 191in | 156in | ▲ HD20+35 in · +22% |
| Width | Not recorded | 94in | — |
| Height | 95in | 124in | ▲ D6D SA Special Application+29 in · +31% |
| Operating Weight | 41,000lb | 29,000lb | ▲ HD20+12,000 lb · +41% |
Hydraulics
| Spec | Allis Chalmers HD20 | Caterpillar D6D SA Special Application | Difference |
|---|---|---|---|
| System Type | Not recorded | Open Center | — |
Electrical
| Spec | Allis Chalmers HD20 | Caterpillar D6D SA Special Application | Difference |
|---|---|---|---|
| Starter Type | 24 volts | Electric Starter | — |
Capacities
| Spec | Allis Chalmers HD20 | Caterpillar D6D SA Special Application | Difference |
|---|---|---|---|
| Coolant | 15gal | 10gal | ▲ HD20+5 gal · +50% |
Operator Station
| Spec | Allis Chalmers HD20 | Caterpillar D6D SA Special Application | Difference |
|---|---|---|---|
| Type | Not recorded | Open | — |
Category context
Both models against the field
Engine Displacement
median 284 ciA · 76th percentile (660 ci)B · 75th percentile (638 ci)
Cylinders
median 4A · 88th percentile (6)B · 88th percentile (6)
Forward Gears
median 5A · 1st percentile (2)B · 65th percentile (6)
Operating Weight
median 9,127 lbA · 97th percentile (41,000 lb)B · 88th percentile (29,000 lb)
Length
median 125 inA · 86th percentile (191 in)B · 71st percentile (156 in)
A · HD20B · D6D SA Special ApplicationMedian Industrial Tractor