Heikki Kovalainen's McLaren topped the time charts during a quiet day of testing at Jerez.
With Renault and Brawn GP wrapping up their testing schedules yesterday, only McLaren and Williams remained out on the track for day four of testing.
The woking-based outfit showed considerably more speed than in previous days, with Kovalanien clocking a fastest time of 1:18.202 during his 79-lap run.
The Finn's time was the third fastest of the week, with only Jenson Button and Nico Rosberg recording quicker times.
Kazuki Nakajima's Williams was 1.8 seconds off the pace of his competitor, with a time of 1:20.014.
01. Kovalanien McLaren 1:18.202 79 laps
02. Nakajima Williams 1:20.014 103 laps
Source : Planet F1