The first generation of Chevrolet Impala was introduced for the 1958 model year. The Impala was introduced as the top trim level for the Chevrolet Bel Air, and was available in two door hardtop or convertible body styles that featured different bodywork from the front windshield rearward. A standard 4.6L V8 engine was offered, as well as an optional 5.7L V8. This first generation Impala was only available for the 1958 model year. For 1959, the Impala became a separate model with the Second Generation Chevrolet Impala.