Carpentier leads practice in Chicago

The Canadian was followed by team-mate Greg Moore, and Roberto Moreno - who is standing in for injured Christian Fittipaldi at the Newman-Haas team.

Champ Car teams were testing at the new circuit, which makes its first appearance on the CART series calendar this weekend.

Carpentier was quickest averaging 156.734mph, while Moore achieved 156.054mph and Moreno 155.771mph.

Rookie Juan Montoya was well off the pace, with a speed of 153.461mph - which placed him 17th.

However, championship leader Dario Franchitti struggled even further down the field averaging 151.441mph - which saw him 25th.

'You have to really jump on the brakes hard in the turns,' said Walker Racing driver Gil de Ferran. 'The turns are wide, but you really have to slow down to get through them.

'The straightaways are long and you're really flying, and then you have to go through the turns about 120 miles an hour.'

There will be another full day of practice in Chicago today, followed by qualifying tomorrow for Sunday's 225-mile race.