McLaren's Lewis Hamilton topped the Barcelona timesheets for the second day running on Tuesday in Formula One's final pre-season test before the Australian season-opener on March 16.
The 23-year-old, overall runner-up last year in his debut season, lapped the Circuit de Catalunya in one minute 21.234 seconds with new Finnish team mate Heikki Kovalainen second quickest in 1:21.434.
Ferrari's world champion Kimi Raikkonen was third in 1:21.722, with Germany's Nico Rosberg fourth for Toyota-powered Williams.
McLaren said they had concentrated on pit stop practice and simulated qualifying in the morning with longer runs in the afternoon.
Renault's Spanish double world champion Fernando Alonso was only 13th on the timesheets with Brazilian team mate Nelson Piquet Jr 18th.
"We still need to find some performance in the car and some pace," said Alonso in a team statement. "But we have the potential and we just need to discover it.
"There is only one day of testing left and we need to fully attack tomorrow to make the most of it."
Toro Rosso's German driver Sebastian Vettel turned out for sister team Red Bull after David Coulthard suffered a trapped nerve in his neck on Monday and was rested as a precaution.
Ferrari-powered Force India, who gave their new car its track debut at the circuit on Monday, had another strong day with Italian Giancarlo Fisichella sixth fastest.
"I am happy with the new package, it is better with more downforce and has more stability," said Fisichella. "But we still have got something more for the first race so it looks quite encouraging."
