McLaren Mercedes on Thursday returned to familiar territory atop time sheets at Formula One testing in Jerez de la Frontera, Spain, although interlopers Red Bull and Williams whistled into second and third spots, respectively.
Finn Heikki Kovalainen, simulating qualifying, tooled to a quick lap of 1 minute, 17.974 seconds in setting the top time in an MP4-23. David Coulthard drove an RB4 to a 1:18.485, and Kazuki Nakajima took an FW30 to a 1:19.117.
Sunny conditions gave way to clouds with some wind by day's end but weather failed to intercede as it had the day before and teams were able to work on aerodynamic development as well as make long runs to test systems at race distances.
"The primary focus of the test this week has been pushing forward with the aerodynamnic program," McLaren chief operating officer Martin Whitmarsh said. "There was some disruption to this on Wednesday and Thursday due to the windy conditions. However, the test team have been able to complete the proving process in a range of aerodynamic components."
He said the team's final seven days of testing will share track time in Barcelona at the end of February with "all the leading teams", meaning Ferrari will be present. Ferrari and Toyota skipped this date in southern Spain after testing through the weekend in Bahrain.
"Whilst this will give us the possibility of a more comprehensive comparison, we will nevertheless focus on our own test program rather than chase times," he said. "The real litmus test of performance will take place in Australia."
Teams start shipping cars and equipment March 6 for the season opener in Melbourne on March 16.
Coulthard and teammate Mark Webber (1:19.980) drove 107 laps each in the RB4s as reliability and good weather provided high mileage testing.
"Overall, this has been a very good test for us, as we got through all our program and completed more laps than planned," Red Bull chief test engineer Ian Morgan said. "Over the three days, we did a lot of aero and mechanical work with no major problems and we can look forward to the remaining preseason tests in Barcelona with confidence."
Nakajima again stuck a Williams near the sharp end of charts in completing 90 laps. Test driver Nico Hulkenberg had a more difficult time; he completed 71 laps with a best time of 1:21.116, third slowest among 16 drivers testing for nine teams.
Nelsinho Piquet racked up the most laps, 134, in a Renault R28. He followed McLaren's Lewis Hamilton (1:19.429 in 83 laps), BMW Sauber's Robert Kubica (1:19.535 in 129 laps) and Scuderia Toro Rosso's Sebastian Vettel (1:19.688 in 53 laps) on the unofficial time chart with a quick lap of 1:19.817.
"I definitely feel I'm getting used to the physical demands of F1," Piquet said.
Piquet's Brazilian countryman test driver Lucas di Grassi set a fast lap of 1:22.288.
Kubica and BMW Sauber teammate Nick Heidfeld worked on aero and long runs as well as practice starts and pit stops in a day that improved balance on the F1.08s. Heidfeld ran a quick time 1:19.934 in 116 laps. Pole Kubica again outpaced his German teammate in winter testing.
Toro Rosso's Vettel completed the fewest laps. His STR2B suffered a clutch problem then an electrical hangup. Teammate Sebastien Bourdais managed to complete 101 laps after a water leak was fixed. The French rookie who is current Champ Car World Series titlist drove a fast lap of 1:19.848, good for eighth-best.
Italian veteran Giancarlo Fisichella spent 89 laps in the Force India VJM01 working on gearbox and electrical systems in a day that went smoothly as he ran to a quick lap of 1:20.669, 11th on the time chart.
"Today was a good day," Fisichella said. "We were able to put in a lot of laps without any major problems, and I felt comfortable in the car. We worked through a program of set-up and some development items, and even with a reasonable fuel load we were still able to put in some competitive times."
Fisichella was followed by Jenson Button whose 121 laps in the Honda RA108 produced a quick lap of 1:20.988. Alex Wurz drove the second RA108 to a quick lap of 1:21.605 in 103 laps.
"We spent the test this week working on reliability runs and engine driveability, and I am very pleased that we have found some improvements," Wurz said. "We also completed a full race simulation today, which went very well."
Head of race and test engineering Steve Clark said the Jerez test gave the Honda team an understanding of what has affected handling.
"The new components to address these issues will be ready in time for our next test in Barcelona," he said. "With this in mind, the focus this week was to sign off the race distance reliability of the car with Jenson and Alex completing full race distances today. We also made steady progress with improving the engine driveability and chassis controls, which will give us a good starting point for the next test when we will be in a position to implement the new updates."
Englishman Anthony Davidson returned to an F1 seat for the first time since December in running the Super Aguri interim car, the SA07B, to a 1:21.010 in 103 laps. The team continued to focus on electronic systems development in advance of new rules dictating a standard electronic control unit.
"We got a lot of positive runs in and completed 103 laps with everything running reliably," Davidson said. "We continued learning about the MES system from team and driver perspectives, and I think that we made good progress overall today."