The Alfa Romeo straight-eight would return after World War II to dominate the first season of Formula One racing in 1950, and to win the second season against competition from Ferrari's V12-powered car in 1951. The Alfa Romeo 158/159 Alfetta was originally designed in 1937 and won 47 of 54 Grands Prix entered between 1938 and 1951 (with a six-year gap in the middle caused by the war). By 1951, their 1.5 L supercharged engines could produce at 9,300 rpm, and could rev as high as 10,500 rpm. However, the engines were at the end of their potential, and rule changes for the 1952 season made the Alfettas obsolete.