Stoner won the world title in just his second season in MotoGP

The 22-year-old Australian is confident the new Ducati, which was unveiled in Italy on Tuesday, will serve him well when the season begins in March.

"I am calmer than a year ago. It is like I've had a weight lifted off my shoulders," said Stoner, who won 10 races en route to the 2007 title.

"Now I know I can go even better and that we can repeat it."

Stoner is also ready to be driven on by new Italian team-mate Marco Melandri, who joins Ducati from Honda.

"If Marco Melandri races faster than me and he wins, I'll be happy for him," said Stoner. "He's got talent and he will prove it to us."

Meanwhile, Melandri, who finished fifth in the championship last season, accepts that Stoner is the team's main rider.

"Casey Stoner has won the world title on this bike and therefore I expect to be number two.

"I am new and it would be stupid to think of coming to the team of the world champion and being number one," the Italian said.