| MODEL | NSU 2.5 HP 1903 - 1905 |
| Year | 1903 - 1905 |
| Engine Type | Single cylinder, 4-stroke |
| Displacement / Capacity | 331 cc / 20.2 cu in |
| Bore X Stroke | — |
| Compression Ratio | — |
| Cooling System | Air-cooled |
| Max Power | 1.8 kW / 2.5 hp @ 2000 rpm |
| Max Torque | — |
| Ignition | Magneto |
| Induction | — |
| Start System | Bicycle-type pedal |
| TRANSMISSION SPECS | |
| Lubrication | — |
| Gear Box | — |
| Clutch | — |
| Final Drive | Chain |
| CHASSIS SPECS | |
| Frame | Steel, open frame with engine as stressed part |
| Front Suspension | — |
| Rear Suspension | — |
| Front Brakes | — |
| Rear Brakes | — |
| DIMENSION SPECS | |
| Overall Length | — |
| Overall Width | — |
| Overall Height | — |
| Seat Height | — |
| Wheelbase | — |
| Ground Clearance | — |
| Dry Weight | — |
| Wet Weight | — |
| WHEEL SPECS | |
| Front Tyre | — |
| Rear Tyre | — |
| FUEL SYSTEM | |
| Fuel Capacity | — |
| Fuel Consumption | — |
| Top Speed | 50 km/h / 31 mph |
The first NSU to use an engine of the firm's own design, built at Neckarsulm. Unlike the earlier bought-in motor it was not slung from the frame but formed part of an open frame, and it used an automatic inlet valve with mixture regulation.
