The most-noted aspect of the season was Ferrari's lack of pace caused mainly by a new rule prohibiting tyre changes during the course of a race. The Bridgestone tyres used by Ferrari could not find the right balance between performance and reliability, leaving the Michelin runners to battle for race victories.[3] Further rule changes emphasised the new focus on reliability, with engines required to last two Grands Prix without being changed.
Renault appeared the fastest team in pre-season testing and it was no surprise they dominated the early fly-away rounds. Giancarlo Fisichella won the season opener in Australia before teammate Alonso demonstrated his title credentials with a series of victories in Malaysia, Bahrain and San Marino. As the season progressed the McLarens of Kimi Räikkönen and Juan Pablo Montoya became increasingly competitive and by the latter stages of the season the McLaren was generally considered the faster package. However, constant technical failures meant neither the team nor Räikkönen were able to translate their speed into Championship success.
Alonso secured his Drivers' Championship with a third-place finish in the Brazilian Grand Prix. Despite both he and Räikkönen having six victories to their name at this point in the season, Alonso's greater consistency meant he was able to claim the Championship with two rounds to spare. The Constructors' Championship was secured by Renault at the final race, with Alonso's seventh victory of the year. This gave Renault their first championship as a constructor (after only previously triumphing as an engine supplier) despite winning two fewer races than McLaren.
Ferrari finished third in the Constructors' Championship with only one win, at the United States Grand Prix, a race that was only contested by the six Bridgestone cars after Michelin declared their tyres unsafe to run in the Indianapolis Motor Speedway's unique banked corner.[4]
After a high-flying 2004 season the most conspicuous drop in performance after Ferrari was BAR-Honda, who were banned from two races after scrutineers in San Marino discovered a hidden fuel compartment that allowed their cars to run underweight. They were beaten in the Championship by Williams, whose engine partner BMW had announced they were leaving to join Sauber in June, and Toyota, who achieved 5 podium finishes and were only beaten to third in the championship because of Ferrari's 1–2 in Indianapolis.
All the teams scored world championship points over the course of the season, Minardi scoring rare points in their final season courtesy of being able to run in the US race.
