ZIL-4104
The ZIL-4104 was a limousine built by ZIL from the late 1970s to the early 1980s, when it served as the transport of the elite of the Soviet Union. It is estimated that no more than fifty cars were produced each year. Originally designated ZIL-115, the ZIL-4104 was an update of the ZIL-114 with which it shared the same chassis and over half its mechanical components. Despite sharing the same chassis, the ZIL-4104 was as much as 314 kg (692 lb) heavier than the 114. Mechanically, the ZIL-4104 also improved on the 114. The pushrod V8 engine of the  114 had its stroke increased from to . With a bore, this meant the capacity increased from to , which was throughout the model's lifespan one of the world's biggest passenger-car engines (Cadillac offered a engine, enlarged to ). This engine developed 315 hp SAE Gross at 4,400 revs per minute and a substantial at 2500 rpm. The car weighs , is long, wide, and high. Among its special features were special laminated windscreen and triple-layered windows, supposedly offering protection from radiation in case of nuclear attack, plus duplicated systems, including dual ignition, two 74-amp batteries in parallel, and  two fuel pumps. The console and dash were covered with Karelian birch thick, and the rear seat controlled radio (a "Riga" receiver), power windows, heater, and air conditioner; in the console in front was a "Vilma" cassette player. The fuel tank was and the car used leaded 95 octane petrol, getting . By 1984, a new three-speed automatic transmission had replaced the much outdated two-speed type that had been used by ZIL dating back to the first ZIL-111 in 1958. As official state cars, the ZIL-4104s were "built under conditions of strict secrecy" and were "maintained in closed garages  by a special division of the KGB", with everyone involved in building and servicing them sworn to secrecy. ZIL-41044 and ZIL-41042. In the later years of the 4104 production run, ZIL introduced two derived models based on the 4104 chassis and the shortened ZIL-117 chassis not previously used with the 7.7 litre engine.