The work on the Formula 1 Renault R25 for the 2005 championship mainly concerned aerodynamics and chassis, to make the car's behavior more predictable than that of the R24. Equipped with the 2998cc V10 type RS54 engine, the R25 allowed Fernando Alonso to win his first F1 world title. His teammate Fisichella finished in fifth place. Renault took the constructors' title ahead of McLaren-Mercedes and Ferrari.