LMP2 cars concern Audi boss

While the two Audi R10s qualified on the front row for the American Le Mans Series season opener, the lead Porsche RS Spyder of Penske Racing was just one second behind the pole-sitting car.

"As we expected, the LMP2 cars are not much slower," said Ullrich. "This means we have to work on a good strategy for the race."

The Audi team hadn't expected a strong threat from the Porsches and Acuras at the first round of the season, as the circuit should suit the LMP1 cars more than the smaller prototypes.

While Audi are contesting the entire ALMS season with two cars this year, the team are clearly focused on the importance of Sebring for their Le Mans preparations, as they get ready for Peugeot's arrival later this year.

Seven-time Le Mans winner Tom Kristensen has not driven the car since June, and he was impressed with how the R10 has improved in the months since.

"We naturally try to win here at Sebring," he said. "It is a tough race itself, but of course it is good preparation for Le Mans in June. We definitely will not underestimate Peugeot's effort."