12 material differences
Tractor oneDavid Brown 990 Selectmatic1965–1979No measured PTO figureTractor twoPorsche-Diesel Master 4081958–1960No measured PTO figure
Which should you choose?
Read our verdict on the 990 Selectmatic and the Master 408 → It is generated from the rows below by a fixed, versioned rule set, and names the figure behind every call.
Field by field
12 material differences · 0 fields identical or within 5%, which is not counted as material
| Field | 990 Selectmatic | Master 408 | Gap |
|---|---|---|---|
| Engine | |||
| Engine power, claimed claimed | — | 49.1 hp | — |
| Engine declared | DAVID BROWN AD 4/47 or AD 4/49 A (B) | Porsche-Diesel F 408 | differs |
| Displacement declared | — | 3.29 L | — |
| Maximum torque declared | 140 lb·ft · 190 N·m | 132 lb·ft · 178 N·m | +7% 990 Selectmatic |
| Transmission | |||
| Top speed declared | 15.5 mph · 25 km/h | 12.1 mph · 19.5 km/h | +28% 990 Selectmatic |
| Clutch declared | pedal-operated dry Borg & Beck single-disc clutch | Hydraulic Voith fluid coupling and Fichtel & Sachs double dry clutch | differs |
| Hydraulics & hitch | |||
| Pump flow declared | 7.3 gpm · 27.5 L/min | 6.6 gpm · 25.0 L/min | +10% 990 Selectmatic |
| Rear PTO speeds declared | 540 rpm | 540 | differs |
| Weight & dimensions | |||
| Unladen weight declared | 5,688 lb · 2,580 kg | 5,401 lb · 2,450 kg | +5% 990 Selectmatic |
| Wheelbase declared | 78.7 in · 2,000 mm | 97.0 in · 2,465 mm | +23% Master 408 |
| Length declared | 126.0 in · 3,200 mm | 143.7 in · 3,650 mm | +14% Master 408 |
| Width declared | 67.0 in · 1,702 mm | 73.4 in · 1,865 mm | +10% Master 408 |
| Ground clearance declared | 21.4 in · 543 mm | 17.2 in · 437 mm | +24% 990 Selectmatic |
| Turning radius, braked declared | 10.3 ft · 3.14 m | — | — |
| Fuel tank declared | 64.9 qt · 61.4 L | 48.6 qt · 46 L | +33% 990 Selectmatic |
Height is not in this table. It is not one measurement: the sources measure it to different points — over the cab on some machines, over the steering wheel or the exhaust on others — and the same tractor measured two ways can differ by most of a metre. It appears here only when both machines' figures carry the point they were measured to and it is the same point, which is not the case for these two. Each machine's own page prints its height as its source gives it.
David Brown 990 Selectmatic sources
- Source: Traktorenlexikon, “David Brown 990”
Porsche-Diesel Master 408 sources
- Source: Traktorenlexikon, “Porsche-Diesel Master N408”