Singapore: Red Bull signalled it was ready to resume its fight for the Formula One title with a strong performance in Friday's practice for the Singapore Grand Prix.
Reigning world champion Sebastian Vettel topped the time sheets in both sessions, while team-mate Mark Webber was fourth in the second practice. Neither driver had finished their previous race, the Italian Grand Prix on September 9.
"Overall we can be happy with today, but let's see what we do tomorrow, it's still Friday and today's results are not so conclusive as some drivers got stuck in traffic," Vettel said. "Most important is that the car seemed to work on either tyre, so we go from there."
McLaren's Jenson Button was second fastest ahead of championship leader Fernando Alonso of Ferrari, with the presence of three different teams in the top three places indicating a close fight in Sunday's race.
"I would say today was positive, even if the first impression is that we are not as competitive as we were in Monza, two weeks ago," Alonso said. "We still lack a bit of performance on tracks like this one, where you need maximum aerodynamic downforce."
Button's team-mate Lewis Hamilton was fifth, seven tenths of a second off Vettel's time.
The other title contender, Kimi Raikkonen of Lotus, was down in 12th — a full two seconds behind Vettel — after missing the closing stages of the second session with hydraulic problems.
"Usually we improve on Saturday time-wise but we are not suddenly going to catch up two seconds to the front," Raikkonen said. "I am sure they will improve also, and it shows that we are not as fast as we should be."
Michael Schumacher of Mercedes also sat out the final minutes due to brake problems.
While there were no major incidents on Friday, plenty of drivers ran wide and flirted with the tight concrete walls as they tested the limits of the street circuit and came to grips with a slippery, dusty surface.
Williams driver Bruno Senna clipped the wall heavily and stalled his car, bringing out the red flags midway through session two, and ending his night.
Vettel won this race last season, but his dominance of 2011 is now a distant memory, having won only one race in this campaign. Friday's performance should provide a timely boost for him and the team — particularly as there were no signs of the alternator failure which had plagued the Red Bulls in Italy.
Most teams were running very different settings in Singapore than in Italy, switching from the high speeds of Monza to the twists and turns of Marina Bay.
The biggest change was made by Mercedes, which had a new exhaust system that directed air to the rear wing and rear diffuser to improve traction. Friday's performance, with Schumacher 11th and Nico Rosberg in eighth, showed the team had more work to do to integrate it to the chassis.
Sahara Force India pair Paul di Resta and Nico Hulkenberg were sixth and seventh fastest in an encouraging performance for the Silverstone outfit, while Ferrari's Felipe Massa was ninth and Lotus' Romain Grosjean 10th in his return to action after serving a one-race suspension.