BERLIN, Germany - Red Bull should have no grounds for complacency as it attempts to win a fourth successive Formula 1 title for team and driver, World champion Sebastian Vettel told DPA in an interview.Vettel acknowledged the pressure would be on him as he goes into Sunday's (March 17) Australian GP as the driver to beat in the 2013 season after a hat trick of titles."The fact is we won the last three titles which wasn't child's play but a hard battle," the 25-year-old German said. "Despite the success the whole team should not lie back. You have to try right from the start to get an advantage over the other teams, and then the pressure is always on because you have to defend this advantage."It all starts from zero and everyone has the same conditions. I love the sport and the challenge."GOING FOR FOURVettel said Red Bull had not felt any need to change its approach ahead of the new season but was always looking for ways to improve and was open to changes. A fourth title would mean "a great deal" to him. Only two drivers - Juan Manuel Fangio and Michael Schumacher - have won four in a row."I want the World championship trophy to stay in my cabinet. That's the reason I compete in F1," he said.However Vettel said it was difficult to gauge the team's or their rivals' performance from the pre-season testing in Jerez and Barcelona. "It's always difficult to assess where we and the others stand. Actually everybody only reveals their hand in qualifying in Melbourne."MELBOURNE WON'T TELLSunday's opening race of the season will not necessarily be a guide to the rest of the year because the race in Melbourne was "very specific". "In addition the season is very long, and as we saw last year the title was decided in the last race," Vettel said. "I think we will know a little bit more after four races, but it also won't be more than a trend. Of course, we can assume that the big teams will again be at the front."Vettel beat Ferrari's Fernando Alonso to the title in 2012 by three points, and asked to define his relationship with the Spaniard, Vettel replied, "He is my opponent on the track like any other opponent."Despite Vettel's three world titles, Red Bull has said there will be no preferential treatment for him over 36-year-old Australian team mate Mark Webber, a situation which Vettel accepts."Red Bull's philosophy was always for there not to be a number one driver," Vettel said."It makes competitive sense when each driver has equal opportunity. Nothing new there, we are just staying true to ourselves." Stay with Wheels24 for the 2013 Formula 1 season – fresh reports every day.