The Alfa Romeo BAT is an Italian concept car. The car originated from a joint collaboration project between Alfa Romeo and the Italian design house Bertone that began in 1953. Three cars were built: the BAT 5 in 1953, the BAT 7 in 1954, and finally the BAT 9 in 1955. All three cars were designed by Franco Scaglione.
Alfa Romeo contacted Giuseppe "Nuccio" Bertone of the Bertone design house and commissioned three concept vehicles to research the effects of drag on a vehicle. The idea was to create vehicles with the lowest possible drag coefficient. The cars were named BAT for "Berlinetta Aerodinamica Tecnica." All the cars featured large rear bumpers and curved fins. They were built upon the Alfa Romeo 1900 chassis. Each of the three cars was presented at the Turin Auto show, in 1953, 1954 and 1955 respectively.
The lowest of the three cars' drag coefficient was 0,19, an achievement even by today's standards. For each of the cars, Alfa Romeo provided a five-speed gearbox and a powerful four-cylinder engine that produced more than 90 horsepower (67 kW), good enough to propel the car to a top speed of 125 mph (201 km/h).
All three original BATs have been restored and are on long-term exhibition at the Blackhawk Museum in Blackhawk, California since 2005. They also make appearances at car shows such as the annual Concorso Italiano in Monterey, California.
The BAT 5 was the first of the Bertone-Alfa Romeo BAT project. It was first shown at the Turin Auto show in 1953. The design of the model was based on a study of aerodynamics. The shape of the front in fact aims to eliminate the problem of airflow disruption at high speeds. The design also aims to do away with any extra resistance generated by the wheels turning, as well as achieving a structure which would create the fewest possible air vortices. In practice these rigorous criteria would allow the car to reach 200 km/h (120 mph) with the 100 hp (75 kW) engine mounted as standard. The design that Bertone came up with was for an extremely light car (1,100 kg (2,400 lb)), with side windows at a 45 degree angle with respect to the body of the car and a large windscreen which blends in with the almost flat roof. The tail has a length-ways rear windscreen divided by a slim pillar, and two fins tapering upwards and slightly inwards. The car had a drag coefficient of 0,23.