Finland's 2007 Formula One world champion Kimi Raikkonen set the fastest time in his Lotus-Renault during pre-season testing here on Tuesday.
The 32-year-old Raikkonen - winner of 18 grands prix - is putting this year's model through its paces as he returns to Formula One after two years away.
Raikkonen won his 2007 crown with Ferrari before switching to the World Rally Championship in 2009 followed by a spell in Nascar racing.
Double world champion Sebastian Vettel of Germany arrives here on Friday to test the RB8, with his Australian teammate Mark Webber, who is testing the car earlier in the week, clocked the fourth fastest time for Red Bull-Renault on Tuesday.
Testing runs until Friday with further sessions at Barcelona from February 21-24 and March 1-4, before the GP opener in Melbourne, Australia on March 18.
Times and laps: