A new set of rules came into place which introduced qualifying times on aggregate from two sessions with the second on race morning requiring teams to run with race fuel on board and no topping-up allowed pre-race. Of more significance was the stipulation that tyres used for final qualifying had to be kept on the car for the entire race distance. Only a damaged tyre could be changed at pit stops. The one race engine per weekend rule was now extended so that power plants would be expected to last for two race weekends. A change of engine would bring the loss of ten grid positions.

Michelin emerged with a much more competitive tyre than in 2004 and the Bridgestone-shod Ferrari were on the back foot as Renault with Fisichella and Alonso (3) won the first four races. McLaren emerged as mid-season pace-setters with Räikkönen taking three wins, but the excellent season's racing was overshadowed by the fiasco at Indianapolis when the U.S. GP was reduced to a farce after Michelin withdrew its runners on safety grounds.