M25
Inline-8- 25 A 3.4 L · 3,360 cc
359 PS
264 kW · 354 hp à 5,800 tr/min
- 25 C 4.3 L · 4,310 cc
469 PS
345 kW · 463 hp à 5,800 tr/min
- 25 E 4.7 L · 4,740 cc
500 PS
368 kW · 493 hp à 5,800 tr/min
Mercedes-Benz Racing Car · W25 Grand Prix
Silver Arrow — the W25 that began the Grand Prix legend.

Designed for the radical 750 kg weight limit introduced in 1934, the W25 packed a supercharged eight-cylinder into a lightweight frame and body shell where every gram counted. Under Alfred Neubauer's racing organization and with engineers including Rudolf Uhlenhaut entering the competition department, the project marked a decisive turn toward systematic Grand Prix engineering at Mercedes-Benz.
The archive documents just four W25 chassis built between 1934 and 1937 — a minuscule number befitting a pure racing program, but one whose influence far exceeded its production count. The W25 established the Silver Arrow identity and the competitive foundation on which later Grand Prix and sports-racing Mercedes would build.

3 distinct series across 1934–1937 — each identified by its chassis and engine numbers from period factory data.
| Modèle | Millésimes | Châssis | Moteur | Boîte | Total |
|---|---|---|---|---|---|
| W25 | 1937 | 25 | 25 DAB | 1 | |
| W25 | 1935 | 25 | 25 C | 1 | |
| W25 | 1936 | 25 | 25 E | 1 |
* Le chiffre de production publié couvre toutes les séries de ce modèle ; la source ne le détaille pas davantage.


The M25 as fitted to the W25.
359 PS
264 kW · 354 hp à 5,800 tr/min
469 PS
345 kW · 463 hp à 5,800 tr/min
500 PS
368 kW · 493 hp à 5,800 tr/min