Hamilton was eight points behind Vettel in the drivers' championship before that race but won seven of the final 10 races after that while the Ferrari driver won just one.
"This is going to be the toughest battle yet ... their pace is very good at the moment", the Briton said after suggesting in preseason testing that Ferrari could be as much as half a second ahead. The British driver is once again the man to beat after he picked up an incredible fifth world championship last season.
1 - Ferrari driver Vettel is one win away from equalling Schumacher as the driver with the most wins (four) and most back-to-back victories (3 - 2000-02) at the AusGP.
Under different management and after a positive winter testing, Ferrari have arrived in Melbourne with a fast auto and plenty of buzz, raising expectation of a genuine challenge to five years of Mercedes dominance.
"We never sit still so we've got to evolve our track", Westacott said.
The new regulations have changed the front and rear wings, aimed at making it easier for cars to get closer and overtake. We have experience, it's no coincidence that we are world champions so we have to be diligent and stay balanced.' He added: 'But as a driver for sure I have to figure out how can I pull more out, which I don't have the current answer for'.
Hamilton laps up crowd's cheers at F1 season launch party in Melbourne
The four-times champion will bid for a third successive win at Albert Park's season-opener, having foiled pole-sitter Hamilton amid a virtual safety vehicle deployment a year ago.
Lewis Hamilton's teammate Valtteri Bottas has made clear that he no longer wants to be cast in a support role at Mercedes.
The new season boasts a host of driver changes throughout the grid and only two of the ten teams have relied upon last seasons drivers to deliver the goods.
Meanwhile, Vettel sees Charles Leclerc, who joined Ferrari from Sauber in a swap for the experienced Kimi Raikkonen.
Vettel is a victor and having to settle for second in the drivers and constructors championship previous year was tough to take.
"In terms of the team, we've got so many incredible people within the team, and the energy.it's inspiring to see so many people so pumped, pulling together".
Alleged Gambino Crime Family Boss Frank Cali Shot Dead Outside Home
As he strolled out of his red-brick mansion on Staten Island the reputed mob boss Francesco "Franky Boy" Cali probably felt safe. Francesco Cali, 53, was found with multiple gunshot wounds to the torso in the NY borough of Staten Island , the NYPD said.