5 material differences · fewer than 12
Tractor oneBührer OP-17 Standard (A)1969–1975No measured PTO figureTractor twoDavid Brown 990 Implematic1961–1965No measured PTO figure
Which should you choose?
We will not advise between these two machines, because the drive differs (Two-wheel or four-wheel drive; 2WD); they were not built in overlapping years (1969–1975; 1961–1965). The figures below are side by side so you can judge them yourself; each says whether it was measured, claimed or declared by its source.
Field by field
5 material differences · 4 fields identical or within 5%, which is not counted as material
| Field | OP-17 Standard (A) | 990 Implematic | Gap |
|---|---|---|---|
| Engine | |||
| Engine power, claimed claimed | 45.3 hp | 52.0 hp | +15% 990 Implematic |
| Engine declared | PERKINS 203 U (AD 4.203) | DAVID BROWN AD 4/47 A | differs |
| Displacement declared | 3.33 L | 3.04 L | +9% OP-17 Standard (A) |
| Maximum torque declared | 153 lb·ft · 208 N·m | 141 lb·ft · 191 N·m | +9% OP-17 Standard (A) |
| Transmission | |||
| Top speed declared | 15.5 mph · 25 km/h | 13.7 mph · 22 km/h | +14% OP-17 Standard (A) |
| Hydraulics & hitch | |||
| Pump flow declared | — | 6.0 gpm · 22.7 L/min | — |
| Rear PTO speeds declared | 540 rpm | 540 rpm | — |
| Weight & dimensions | |||
| Unladen weight declared | 4,652 lb · 2,110 kg | 4,771 lb · 2,164 kg | — |
| Wheelbase declared | 79.9 in · 2,030 mm | 76.7–78.7 in · 1,948–1,999 mm | — |
| Length declared | 126.8 in · 3,220 mm | 118.0–121.0 in · 2,997–3,073 mm | differs |
| Width declared | 64.6 in · 1,640 mm | 64.0 in · 1,626 mm | — |
| Ground clearance declared | — | 20.0 in · 508 mm | — |
| Turning radius, braked declared | — | 10.5 ft · 3.20 m | — |
| Fuel tank declared | — | 55.2 qt · 52.2 L | — |
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.
Bührer OP-17 Standard (A) sources
- Source: Traktorenlexikon, “Bührer OP 17 Standard (A)”
- Source: Traktorenlexikon, “Bührer 455/455A”
David Brown 990 Implematic sources
- Source: Traktorenlexikon, “David Brown 990 Implematic”