The Austin-Healey 100-6 was introduced in 1956 for the 1957 model year. The 100-6 was the successor to the Austin-Healey 100, and featured the '6' in its name due to its 2.7L inline six engine. The first variant introduced the BN4. The BN4 was the designation for the 2+2 roadster body style, which ran the whole life of the model. A two seat version of the 100-6 known as the BN6 was available for the 1959 model year. Production of the Austin-Healey 100-6 ended in 1959, and the model was replaced by the Austin-Healey 3000.