Button sets the pre-season test pace

The final day of testing at Jerez saw Jenson Button top the timesheets for McLaren Mercedes with a best lap of 1:18.871s, eclipsing the previous best time of 1:19.299s recorded yesterday by Mark Webber.

Button completed 108 laps in the MP4-25, his best lap on lap 14 two-tenths clear of Robert Kubica in the distinctive new Renault.

It was a busy day for most with eight of the 11 teams completing over 100 laps of the 4.428km Spanish test venue. With the larger fuel tanks required this year due to the refuelling ban, a number of teams opted to complete long runs to evaluate tyre wear while also completing some short runs to test the performance of the 2010 challengers.

Kamui Kobayashi suffered an early mechanical fault on his Sauber Ferrari but was soon back on track, clocking up good mileage in the C29 and ending the day third fastest ahead of Tonio Liuzzi in the Ferrari-powered Force India.

Nico Rosberg completed a number of long runs in his Mercedes and was fifth best while Fernando Alonso tried various setups on the new F10, including long runs to evaluate the softer range of tyres. The double world champion ended the test sixth fastest, but did not seem to be chasing times with a light fuel load.

Jaime Alguersuari was seventh while over at Red Bull, Mark Webber was forced to a halt early this morning with the team opting to change the Renault engine. The Australian resumed his programme finishing the day eighth overall.

Williams lost track time in the afternoon after the FW32 stopped on track with Nico Hulkenberg behind the wheel, ending the day ninth, just over three seconds off the ultimate pace.

Timo Glock was back behind the wheel of the Virgin Cosworth, losing some time in the morning with another hydraulic problem.

Once back on track, the VR-01 failed once again, this time just minutes ahead of the chequered flag. The team has really struggled with reliability this week, achieving just 10 laps on Wednesday, 72 Thursday, 34 Friday and 27 today.

Jarno Trulli tested with Lotus for the first time today completing a number of long runs with relatively heavy fuel loads. His pace on the longer runs not that quick however due to the rear tyres rapidly going off the team explained, with the emphasis on achieving as much mileage as possible ahead of the final tests next week.

Trulli ended the day slowest, but completed an impressive 141 laps over the day.

Overall, it is hard to read too much into the test times, especially given the weather conditions this week, but the standout performances have been from McLaren and Red Bull, while Ferrari can never be discounted and have shown good pace over the longer runs.

Testing resumes next Thursday in Barcelona before the teams pack up and prepare for the Bahrain Grand Prix.