Toro Rosso topped the timesheets at Barcelona today as testing for the 2009 season got underway, just two weeks after the 2008 season concluded in such dramatic style.

With a whole raft of changes being introduced next season, many of the cars looked entirely different to how they looked in Brazil, giving fans a first glimpse of what they can expect next year.

Among the changes in 2009 are the return of slick tyres, a heavily revised aero package and KERS, and while not all the (nine) teams present were running with all the various options it was clear that this is a test with 2009 very much in mind.

Today marked a sensational return to the F1 cockpit for Takuma Sato, who lost his drive with Super Aguri earlier this year when it withdrew from the championship after just four races. The Japanese driver is one of several keen to prove their worth in the weeks ahead and thereby hopefully secure a drive next season.

Sato and Sebastien Buemi, another hopeful for a Toro Rosso seat next season, both completed a high number of laps, making no mistakes, which is commendable, given that both of them only have limited experience of driving the STR3.

However, at the same time, the fact they finished the day fastest and second fastest means even less than usual. Testing times are always hard to evaluate, but today, there was a bigger discrepancy between the car configurations used by the teams and in the Faenza outfit's case the only concession to the new 2009 aerodynamic rules was to run with less downforce. Bridgestone brought its two hardest 2009 slicks and Sato and Buemi spent the entire day on the softer of the two.

According to the team, the results were "encouraging", with both drivers performing consistently, allowing the team to try various mechanical set up changes to see how they affected performance.

Buemi continues testing all day tomorrow, while Sato will run in the morning, before handing over to Sebastien Bourdais.

This week's test will see Honda run two programmes. Alex Wurz and Jenson Button will focus on the development of the 2009 car whilst the team is also evaluating Brazilians Lucas Di Grassi and Bruno Senna.

Wurz kicked off the main test programme evaluating various aerodynamic components for next season and running the Bridgestone Potenza slick tyres. Button will take over the car tomorrow to complete the final two days of the test.

di Grassi was the first of the young drivers to complete his half-day familiarisation programme this morning. He went out for an initial run on grooved tyres to acclimatise to the car before the team fitted used slicks for the remainder of the session. In the afternoon, Senna took to the track for his first ever drive in an F1. He followed the same programme as his fellow Brazilian, starting on grooved tyres before moving to used slick tyres midway through the session.

di Grassi will complete a full day of running tomorrow with Senna taking over the car on Wednesday.

McLaren had Pedro de la Rosa and Gary Paffett on duty, the Woking duo finishing fourth and fifth on the timesheets. Both drivers undertook used cars fitted with slicks and modified to simulate '09 levels of downforce. However, it was the Spaniard, the quicker of the two, who ran with KERS.

BMW, which had Robert Kubica and Christian Klien on duty, worked with two F1.08B interim cars featuring a modified 2008 chassis with some of the bodywork complying to the 2009 regulations. In addition, Klien's car was fitted with BMW's KERS device.