Dixon fastest in de Ferran Acura

Having taken over from team regulars Simon Pagenaud and Gil de Ferran, Dixon lapped in 1:45.671, 0.696 seconds quicker than his Ganassi IndyCar teammate Dario Franchitti, who was driving the Highcroft Acura. Both men are guesting in the American Le Mans Series opener at Sebring in March, and were impressed with the brand new ARX-02a.

"It has one of the most sophisticated designs of any sports car I have seen," said Dixon. "It was great fun to drive the car this week."

Franchitti added: "We still have a long way to go and some things to work on, but when the car is fully sorted out it will be unbelievable."

The Fernandez Racing LMP2 Acura was third, as former Champ Car driver Michel Jourdain Jr joined Adrian Fernandez and Luis Diaz to prepare for the Sebring 12 Hours.

Dyson Racing's new Lola-Mazda made its debut, with Chris Dyson lapping within 0.4 seconds of the Fernandez car.

"The car is fundamentally very good and has a huge amount of potential," said Dyson. "The engine is strong and the car's feedback gives the driver a lot of confidence."

Farnbacher Loles' new 2009-specification Porsche topped the combined times, but the improving PTG Panoz was quickest in the final session, and only 0.3 seconds shy of Richard Lietz and Wolf Henzler's best laps of the day.