M01
Inline-6- 011.4 L · 1,392 cc
26 PS
19 kW · 25 hp at 3,100 rpm
64 N·m
47 lb·ft at 2,000 rpm
Mercedes-Benz Medium Sedan · Typ 400
Early Mercedes-Benz luxury on the W01 chassis.

Ferdinand Porsche drew the 5/25 PS in 1926 as the smallest of three new saloons prepared in haste for the Berlin Motor Show that October, below the two-liter W02 and the three-liter W03. Like its bigger sisters it had six cylinders: a 1,392 cc side-valve unit good for 25 PS and 88 km/h, driving the rear axle through a three-speed gearbox, with rigid axles on semi-elliptic leaf springs and cable-operated brakes on all four wheels.
The board judged a six far too costly for a car of this size, pulled the launch, and told Porsche to design something cheaper. Eight W01s were completed as two-door tourers and saloons and none was ever sold. The follow-up W14 of 1928 substituted a 1,280 cc four and got no further, running to 28 prototypes before it too was dropped.

1 model designation for 1926 — engines, chassis codes and production figures for the W01.
| Model | Model years | Chassis | Engine | Transmission | Total |
|---|---|---|---|---|---|
| 5/25 hp | 1926 | 01 | 01 | 8 |
* The published production figure covers every series of that model; the source does not break it down further.


The M01 as fitted to the W01.
26 PS
19 kW · 25 hp at 3,100 rpm
64 N·m
47 lb·ft at 2,000 rpm