Rossi said while he had to improve his riding skills on the much faster M1, the bike itself had the potential to ensure him victories following the strong and consistent lap times during testing.
"I can start the championship with the target to fight Lorenzo and Pedrosa," adding that he was inspired "one thousands times more than in the last two years.
"Before, you know, you can only fight for the maximum sixth place," he added.
Rossi, 33, said Lorenzo, the reigning champion who also won in 2010, had a good shot for the championship.
"For me, I think he is perfect. He is very fast in all conditions. He is very fast from the beginning. He never makes mistakes and has a high level of concentration. He is at the top," he said.
Lorenzo vowed to work with his former rival.
The pair had a bitter relationship when Lorenzo joined Yamaha in 2008. Rossi, who won four world championships with Yamaha, left to join the Italian team Ducati in 2010.
The second test session will be held at Sepang from February 26 to 28, while the third session will be held in Jerez from March 23 to 25.
The opening round of the MotoGP world championship will be in Qatar under floodlights on April 7.
- AAP