At the end of the 1950 season, a further updated version known as the 159 was produced, which was used for the 1951 season. This version had reworked rear suspension, the old swing axle was replaced with a De-Dion axle and the engine produced around at 9600 rpm. The 159 had top speed of and it weighed . In order to achieve this power however, the simplistically designed engine was fitted with larger superchargers over time. This fact, combined with the rich mixture required to burn methanol in the engine resulted in extremely poor fuel economy - the 159 achieved , compared to the Talbot-Lagos of the time, which delivered . The British Grand Prix at Silverstone was the first Formula One Grand Prix not won by an Alfa primarily because Fangio and Farina both had to stop twice simply to re-fuel their cars – and the Ferrari of José Froilán González did better on fuel and would go on to win the race, with Fangio second. Still, the Alfa had the edge on performance and with wins in Switzerland, France and Spain, Fangio won his first of five championships that year. For their second-to-last World Championship race (until 1979), the Italian Grand Prix at Monza, Alfa Romeo introduced a new evolution version known as the 159M, the "M" standing for Maggiorata ("enlarged").