Vettel is no stranger to success in F1, having won four straight world titles between 2010 and 2013, and past year represented his best season since joining the Scuderia.
The F1 team is set to don trackside uniform designed by Tommy Hilfiger, beginning with the 2018 season.
Hamilton equalled Vettel's total of four titles a year ago and has won three of the last four, finishing second in 2016.
But Hamilton, who is reportedly about to sign a new contract with Mercedes which could earn him up to £40 million (US$55 million) per year, says at 33 he's motivated to blaze on.
"We started talking about it but it's not really my priority at the moment", Hamilton said at a sponsor event, according to Spain's Diario Sport.
"I want to arrive in Melbourne fit".
Hamilton said: "I do not want to retire soon or prematurely". I want to kill it through practice, get pole position and I want to win the race convincingly. "I won some races past year so I know I can do it".
Hamilton has won twice in Melbourne, in 2008 and 2015.More news: Based lawyer to announce first lawsuit in fatal bridge collapse
"We are completely fired up".
The Englishman is favourite to prevail again when the new season begins in Australia on Sunday, and Rosberg believes the likes of Ferrari's Sebastian Vettel and Max Verstappen of Red Bull face an uphill battle.
"I think consistency is definitely going to be the key".
- McLaren are the team with the second-most races (821) to their name, while Renault are the engine suppliers with the second-most races (598) to theirs.
There have been plenty of unflattering comments over F1's new halo head protection device for drivers, with Mercedes team boss Toto Wolff declaring he would take a chainsaw to the safety system if he could because of its weight. However, despite finishing the year with three victories, Bottas had a number of hard races as Lewis Hamilton wrapped up the drivers' championship and he believes he needs to remain more positive if he gets beaten by his teammate.
FIA chief Jean Todt hit back, saying the measure had been introduced to save lives and at the request of drivers' body the GPDA.
"I must only say they are totally insane with this regulation".