Ferrari's new Formula One car made a muted debut on Friday when world champion Michael Schumacher was only 15th fastest in free practice for the Spanish Grand Prix.

Schumacher lapped the Circuit de Catalunya in one minute 18.738 seconds, 1.723 slower than his younger brother Ralf in a Williams.

Brazilian Rubens Barrichello, in the other F2003-GA, was 10th quickest in 1:18.303 as the new Ferrari broke cover at a race weekend for the first time before the afternoon's opening one-lap qualifying session.

Italian Jarno Trulli was second quickest, despite completing just seven laps, on a dry and sunny morning ahead of Renault team mate and local favourite Fernando Alonso.

McLaren's David Coulthard was fourth while championship leader and team mate Kimi Raikkonen of Finland was 18th behind all but the two Minardis.

Schumacher, who did 24 laps to Barrichello's 25, has always finished in the points in Barcelona and has won for the past two years. Ferrari have also given their new car a winning debut for the past four seasons.

The true measure of the new Ferrari's speed is likely to be seen when qualifying starts.

While teams fine-tune settings and work through various programmes in free practice, Friday's qualifying sees all drivers running light on fuel before a more tactical session on Saturday with different loads.