McLaren's Heikki Kovalainen topped the timesheets on the final day of testing at Jerez, the Finn posting the fastest time of the four-day test.

As was the case for all three previous days of the test, conditions were idea, though extremely hot, with the air temperature reaching 32 degrees C and the track temperature hitting 45 degrees.

With Gary Paffett and Pedro de la Rosa running on the previous days, today was Kovalainen's first run in the car this week. The Finn continued the evaluation of the aero development work begun by de la Rosa on Thursday, which saw the car running with the 'rabbit ears' once again. According to the Woking outfit, the test's aero and set-up modifications have both proved extremely positive".

Kovalainen set his best time around ninety minutes into the session, when conditions were cooler. The team has yet to decide whether the 'ears' will be used in Hungary, which is a high downforce circuit.

In the morning, Sebastien Bourdais worked on the evaluation of Spa-spec rear wings, as well as general set-up, while in the afternoon, he switched to the 2009 slick tyres. Bourdais completed 113 laps on his way to posting the second best time of the day.

"The day went quite well," said the Frenchman. "Running the '09 tyres was very interesting, even if a combination of a very abrasive track surface and a 50 degree track temperature, meant they did not last very long! We have also come up with some useful data for Hungary and to be honest that's the most important thing about this test, as 2009 is still a long way away."

After Sebastien Buemi and Mark Webber, it was David Coulthard's turn to strap himself into the cockpit of the Red Bull RB4 for the final day. While the programme earlier in the week included long term development and assessment of the 2009 slick tyres, the Scot focused exclusively on the forthcoming races of this season, only running this year's tyres to end up third quickest on the day.

For Renault, Romain Grosjean, completed 90 laps on his way to posting the fourth best time of the day. Having tested slicks yesterday, the French team was back on grooved tyres today to complete its development programme. That involved continuing with the suspension work the team had started earlier in the week and trying to improve the behaviour of the car in the high temperatures. Grosjean continued to build his relationship with the team, working closely with the engineers and showing good consistency.

"I had a better day today as I already knew the track and I am beginning to feel more comfortable with the car," said the French youngster. "We had a really good morning when conditions were cooler, covering lots of laps and doing some long runs, and we managed to find a good balance with the car. In the afternoon we tried out a few more things with the set-up and tried to make the car more consistent in the high temperatures. So it was another good experience for me and nice to work with the team again."

"It was a good day with Romain," added Christian Silk, "he settled into the programme quite quickly. He was giving good feedback to the engineers and showed consistency on the long runs this morning. So it was another encouraging day with him. We did some work for the forthcoming races with the set-up of the car and also continued evaluating the suspension developments, which have given some interesting results that we will analyse back at the factory."