| Fiat–Materfer 7131 | |
|---|---|
 A 7131 railcar at Cañuelas station, 1990. | |
| Manufacturer | FIAT Ferroviaria Materfer |
| Built at | Italy Ferreyra, Córdoba, Argentina |
| Constructed | 1960-1963 |
| Entered service | 1962-c.1995 |
| Number built | 339[1] |
| Number preserved | 2 |
| Formation | 2-6 cars per trainset |
| Capacity | 72-107 seats |
| Operators | Ferrocarriles Argentinos |
| Lines served | Roca, Urquiza, Mitre, Sarmiento |
| Specifications | |
| Doors | 2 per side |
| Maximum speed | 50 mph (90 km/h) |
| Prime mover(s) | Diesel |
| Coupling system | Buffer and chain |
| Track gauge | 1,435 mm (4 ft 8+1⁄2 in) 5 ft 6 in (1,676 mm) |
The 7131 was an Argentine diesel multiple unit class, first produced in Italy by Fiat Ferroviaria, then licensed to Argentine company Materfer to continue the manufacturing. Those railcars were introduced in the 1960s to replace the existing rolling stock of most of the urban services of Argentina, such as Roca, Urquiza, Mitre and Sarmiento lines.
Following the privatisation of the Argentine railways in the early 1990s, the 7131 fell into disuse, being replaced by other light models built by Materfer. They are commonly nicknamed Chanchas (Spanish for Piggies)