The attractive new Red Bull is looking promising in pre-season testing
Red Bull's Sebastian Vettel outpaced last year's championship runner-up Felipe Massa in testing in Jerez.
The 21-year-old German's fastest lap of one minute, 19.055 seconds was nearly 1.3 seconds ahead of the Ferrari driver's best effort.
Massa was followed by Toyota test driver Kumui Kobayashi, Williams' Nico Rosberg and BMW Sauber's Robert Kubica.
Force India unveiled their McLaren-powered set-up with Giancarlo Fisichella setting a best of 1:21.584.
Giancarlo Fisichella was buoyed after his first day at the controls of his team's 2009 model.
"It's very promising and I felt much more consistency, even under braking, and more stability in the high speed corners," he said.
Lewis Hamilton, Fernando Alonso and Kimi Raikkonen are all due on track on Wednesday, the fourth of five development days.
Vettel, who takes over from David Coulthard at Red Bull this season, was also fastest round the same circuit while testing on 10 February.
Best Jerez Testing times:
Sebastien Vettel (Ger/Red Bull) 1:19.055 (87 laps)
Felipe Massa (Brz/Ferrari) 1:20.330 (63)
Kamui Kobayashi (Jpn/Toyota) 1:20.699 (79)
Nico Rosberg (Ger/Williams) 1:21.171 (71)
Robert Kubica (Pol/BMW-Sauber) 1:21.292 (47)
Giancarlo Fisichella (Ita/Force India) 1:21.584 (31)
Pedro De la Rosa (Spa/McLaren) 1:21.831 (94)
Nelson Piquet (Brz/Renault) 1:22.011 (52)