on 26 October 1997. Originally scheduled as the Grand Prix of Portugal at the Estoril Circuit, the race was moved to the Jerez Circuit when Estoril's management had financial difficulties. The race was added to the schedule after Japan because engine suppliers Renault did not want their last Formula One race to be in Japan. Heading into the final race of the season, two drivers were still in contention for the World Drivers' Championship. Ferrari driver Michael Schumacher was leading with 78 points; Williams driver Jacques Villeneuve was second with 77 points, one point behind Schumacher. Behind Schumacher and Villeneuve in the Drivers' Championship, Heinz-Harald Frentzen was third on 41 points in the other Williams, with Jean Alesi and David Coulthard on 36 and 30 points respectively. Villeneuve had won two more races than Schumacher during the season, meaning that in the event of a tie on points, the rules stated Villeneuve would be world champion. Villeneuve had to finish the race in a points-scoring position (points were awarded for drivers finishing in sixth place or higher) and ahead of Schumacher to become World Drivers' Champion. Schumacher would be world champion if he finished ahead of Villeneuve, or if Villeneuve failed to score any points by finishing lower than sixth or not completing the race. In the World Constructors' Championship, Williams led with 118 points and Ferrari were second on 100. Williams had therefore clinched the constructors' title before the race, as even if Ferrari finished first and second in the race, thereby taking 16 points, and both Williams cars failed to score a point, they could not beat Williams. Following the Japanese Grand Prix on 12 October, the teams conducted testing sessions at various locations around the world. Williams, Benetton, Sauber, Jordan and McLaren conducted at a test session at the Silverstone Circuit. Williams, Sauber and Jordan tested using 1998-spec cars, in preparation for the season. Arrows conducted testing at the Circuit de Nevers Magny-Cours circuit, performing wet weather tyre development with tyre suppliers Bridgestone with the circuit flooded to simulate wet weather conditions. Prost conducted testing at Circuit de Catalunya and performed tyre testing for Bridgestone, as well as testing their 1998-specification car. Ferrari remained at the Suzuka Circuit testing an electronic differential used by driver Eddie Irvine at the previous race. Practice and qualifying Four practice sessions were held before the Sunday race—two on Friday from 11:00