M14
Inline-4- 141.3 L · 1,280 cc
26 PS
19 kW · 25 hp a 3,300 giri/min
Mercedes-Benz Large Sedan · Typ 400
Pre-war luxury on the W14 chassis.

Offered as saloon and cabriolet on the same short chassis, the W14 used a 1.3-liter four-cylinder engine and conventional rear-drive layout. It represented Mercedes-Benz's continued experimentation across the model range in the late 1920s, when the firm was still mapping its post-merger product strategy.
Mercedes-Benz built 56 W14 examples in 1928 — 28 sedans and 28 cabriolets. It was a limited prototype series, not a production Baureihe, and survives today as a rare document of inter-war development work.

2 model designations for 1928 — engines, chassis codes and production figures for the W14.
| Modello | Model year | Telaio | Motore | Cambio | Totale |
|---|---|---|---|---|---|
| 5/25 hp Cabriolet | 1928 | 14 | 14 | 28 | |
| 5/25 hp Sedan | 1928 | 14 | 14 | 28 |
* Il dato di produzione pubblicato copre tutte le serie di quel modello; la fonte non lo scompone ulteriormente.


The M14 as fitted to the W14.
26 PS
19 kW · 25 hp a 3,300 giri/min