team so instead Ferrari began working on an unblown 4.5l car. Much of the year was lost as the team's 2-litre Formula Two engine was progressively enlarged, though when the full 4.5l Tipo 375 arrived for the Gran Premio d'Italia (the final round of the championship) Ascari gave Alfa Romeo their sternest challenge of the year before retiring; he then took over teammate Dorino Serafini's car to finish second. The new Ferrari then won the non-championship Gran Premio do Penya Rhin. Throughout 1951, Ascari was a threat to the Alfa Romeo team though initially he was undone by unreliability. However, after winning at the Nürburgring and Monza he was only two points behind Juan Manuel Fangio in the championship standings ahead of the climactic Gran Premio de España. Ascari took pole position, but a disastrous tyre choice for the race saw the Ferraris unable to challenge, Ascari coming home 4th while Fangio won the race and the title. For 1952 the World Championship season switched to using the 2-litre Formula Two regulations, with Ascari driving Ferrari's Tipo 500 car. He missed the first race of the championship season as he was qualifying for the Indianapolis 500, at the time a World Championship event. He was the only European driver to race at Indy in its 11 years on the World Championship schedule, but his race ended after 40 laps without having made much of an impression, as a result of a wheel collapse. Returning to Europe he then won the remaining six rounds of the series to clinch the world title (also taking five non-championship wins) and recording the fastest lap in each race. He scored the maximum number of points a driver could earn since only the best four of eight scores counted towards the World Championship. Fangio missed most of the season after a crash in the Gran Premio dell'Autodromo di Monza in June. He won three more consecutive races to start the 1953 season, giving him nine straight championship wins (not counting Indy) before his streak ended when he finished fourth in France, although it was a close fourth as the race was highly competitive. He earned two more wins later in the year to give himself a second consecutive World Championship, already becoming Formula One's first two-time champion. Following a dispute over his salary, Ascari left Ferrari at the end of the season and switched to