Fuel tank: 15 of 15 variants rated.
Fiat 131 2000 CL Diesel tops the Fiat 131 ranking by Fuel tank, at 53 L (14.0 gal US).
Across 15 ranked variants, Fuel tank spans from 50 L (13.2 gal US) to 53 L (14.0 gal US).
| # | Variant | Year | Body | Fuel | Fuel tank |
|---|---|---|---|---|---|
| 1 | Fiat 131 2000 CL Diesel | 1982 | Sedan | Diesel | 53 L (14.0 gal US) |
| 2 | Fiat 131 Panorama 2000 CL Diesel | 1982 | Wagon | Diesel | 53 L (14.0 gal US) |
| 3 | Fiat 131 1600 CL | 1981 | Sedan | Petrol | 53 L (14.0 gal US) |
| 4 | Fiat 131 2000 TC Super | 1981 | Sedan | Petrol | 53 L (14.0 gal US) |
| 5 | Fiat 131 Panorama 1600 CL | 1981 | Wagon | Petrol | 53 L (14.0 gal US) |
| 6 | Fiat 131 Panorama 2000 TC Super | 1981 | Wagon | Petrol | 53 L (14.0 gal US) |
| 7 | Fiat 131 2500 L Diesel | 1979 | Sedan | Diesel | 50 L (13.2 gal US) |
| 8 | Fiat 131 2500 Super Diesel | 1979 | Sedan | Diesel | 50 L (13.2 gal US) |
| 9 | Fiat 131 Panorama 2500 Super Diesel | 1979 | Wagon | Diesel | 50 L (13.2 gal US) |
| 10 | Fiat 131 1600 L+1 | 1978 | Sedan | Petrol | 50 L (13.2 gal US) |
| 11 | Fiat 131 1600 CL+1 | 1978 | Sedan | Petrol | 50 L (13.2 gal US) |
| 12 | Fiat 131 2000 Racing | 1978 | Sedan | Petrol | 50 L (13.2 gal US) |
| 13 | Fiat 131 1600 TC Supermirafiori | 1978 | Sedan | Petrol | 50 L (13.2 gal US) |
| 14 | Fiat 131 Panorama 1600 CL | 1978 | Wagon | Petrol | 50 L (13.2 gal US) |
| 15 | Fiat 131 Panorama 1600 TC Supermirafiori | 1978 | Wagon | Petrol | 50 L (13.2 gal US) |