The Pininfarina designed original 456 was available in GT and (from 1996) GTA forms. The difference in name signifies the transmission: the former has a six-speed manual and the latter has a four-speed automatic developed in patnership with FF Developments, in Livonia, MI (which was later purchased by Ricardo Engineering in the UK). This was only the fourth automatic transmission ever offered by Ferrari. The 5.5 L (5474 cc) 65° V12 engine was derived from the Dino V6 rather than the more conventional 60° V12s used in the 412 and Daytona. It produced 436 hp (325 kW; 442 PS) with 4 valves per cylinder and Bosch Motronic 2.7 engine management. It could push the 1690 kg car and four passengers to 302 km/h (188 mph) making it the world's fastest production four-seater. Acceleration to 100 km/h (62 mph) was just 5.2 seconds, with a 13.4 second quarter-mile time. At the time of its development it was the most powerful road car ever developed by Ferrari.
