the rear brakes, dependent on the load being carried (and also the pitch dynamics caused by braking effort and road levels). A centrally located floor mounted handbrake operated on the rear axle using bowden cables. The car's interior had its secondary dashboard switches illuminated by a central bulb with fibre optic distribution to the switches. Series 1, 1974–78 The Fiat 131 Mirafiori was introduced at the 55th Turin Motor Show in late October 1974. The 131 came with a choice of a or OHV inline-four engines, both from the engine family first introduced on the Fiat 124. Both engines were fitted with a single twin-choke Weber 32 ADF downdraught carburettor. A 4-speed manual transmission was standard, with a 5-speed manual and a 3-speed torque converter automatic optional on the 1600 engine only. The initial range comprised eleven different models. There were three body styles: 2-door saloon, 4-door saloon and Familiare station wagon (Estate on the British market). Station wagons were built by SEAT in Spain, but were labelled Fiats for all non-Spanish markets. Trim levels were two; the entry-level 131 Mirafiori (also known as "Normale" or "Standard") had single square headlamps, wheels and dished hubcap from the 124, and simplified interior furnishings. Next was the better appointed 131 Mirafiori Special (or simply "S"), which could be distinguished from the base model by its quadruple circular headlamps, specific grille, side rubbing strips, chrome window surrounds, and rubber bumper inserts. Inside it added different instrumentation with triple square dials, a padded adjustable steering wheel, cloth upholstery, and reclining seats. Additionally the more sophisticated options—such as air conditioning, tachometer, limited slip differential and vinyl roof—were exclusive to the Special. Each body style could be combined with either of the engines and trim levels—save for the Special estate which only came with the larger engine. US market versions had a SOHC 1.8 litre inline-four and were available with a GM three-speed automatic transmission. Salvatore Diomante's Autocostruzioni S.D., located near Turin, offered a nearly 5-metre long "131 Diplomatic" limousine conversion. {| class="wikitable" style="text-align:center; font-size:90%;" ! Model || Engine code || Engine type ||style="line-height:1.2em;"| Displacementbore × stroke || Carburetor || Power |- |style="line-height:1.2em;"| Mirafiori 1300 |rowspan=3| 131A.000 || rowspan="7" | OHV I4 ||rowspan=3| || rowspan="7" | single twin-chokeWeber 32 ADF ||rowspan=3| |- style="line-height:1.2em;" | Mirafiori Special 1300 |- style="line-height:1.2em;" | Familiare 1300 |- |style="line-height:1.2em;"| Mirafiori 1600 |rowspan=4| 131A1.000 || rowspan="4" | || rowspan="4" | |- style="line-height:1.2em;"