One more title could be enough to satisfy Lewis Hamilton's ambition, according to fellow triple world champion Sir Jackie Stewart.

Hamilton has always said that his goal was to match the championship tally of another triple title winner, Ayrton Senna, but the 31-year-old has just commenced the quest for a fourth.

"He will win more than three world titles," Stewart told German broadcaster Sky at the Australian Grand Prix. "At least four or five.

"Maybe with his lifestyle he will say 'After the fourth title I will go into the music business'."

Indeed, Hamilton's off-track interests are notably growing, as he delves into the worlds of music, fashion and celebrity.

"With his chains and his earrings he attracts a lot of attention, but that's his style," said the 76-year-old.

"For certain markets this is certainly positive, but it is unconventional for Formula 1.

"He has made a lot of money and has been incredibly successful. He is now 31; I retired at 34."

Hamilton finished second in Melbourne, behind Mercedes teammate Nico Rosberg.