World champion Sebastian Vettel believes Red Bull will need to take another step forward this season in order to retain the crowns won last year.
Vettel became the youngest ever world champion last season after charging to the top with victory in the final race of the season in Abu Dhabi.
Now the German admits Red Bull will have to work extra hard in order to continue on top now his team will be the hunted one.
"Whatever we achieved makes us all very proud and no one can take it away from us, so I think that is a huge plus, but we start here, four tests to go and 20 races to go," Vettel said during the launch of the 2011 car.
"Everyone starts with zero points so everyone has the same chance to win the world championship this year.
"It will be a tough battle and a long hard fight so I think we need to focus again and motivation is not a problem. I think as a sportsman naturally we are looking forward to achieve the next thing.
"Obviously it is a difficult situation that we are in now, probably more difficult than we were in last year when we said 'Right let's focus and go for the title', and this year is a different story.
"We have to try to defend it, but we have to develop from how we were last year otherwise we do a step back and the others pass us. We have to stay focused and try learning every day and try to get better otherwise.
"Naturally that is what the others do after they got defeated last year, they try to get better, so if we approached the year the same as last year we would not move forward, so we need to try to move forward again."
Vettel, who got his first taste of the new Red Bull RB7 at Valencia on Tuesday morning, conceded it is very hard to predict how the season will develop.
But he claimed his team is not afraid of having pushed the limits with the design of the new car in order to make it more competitive.
"I think winning the championship, no matter when or for whom never comes easy," he said. "As I have said many times now, we have a lot of races this year and a lot of things that will possible change through the season.
"So even if you start with one of the quickest cars you might be facing a second half of the season with a car that is potentially not quick enough or the other way around, so it is difficult to predict.
"It is the usual stuff, we never started the season being afraid of what we had. Sometimes F1 cars are built on the limit so it's not impossible that something breaks down.
"We had some issues with reliability at the beginning of last year, others had some issues at the end so you might think reliability might be the last potential problem to have but that is how F1 goes sometimes and that is the exciting bit. That is the challenge, at the end of the day."
The world champion admitted he cannot take for granted that the new Red Bull will be the car to beat again, although he is very confident the team has managed to produce another winner.
"For some reasons, we have people on board who work in a smart and clever way and who build a very strong package," he said. "It is not as if we fired all those people at the end of the season and I had to build the car on my own.
"I think as drivers we all rely on each other and it is usual situation in the team, we have those strong and important people on board so I am confident we will have a good package again this year but you never know until you see all the rest of the other cars and maybe someone came along with a very smart idea you haven't thought of.
"So it's not automatically given that you have the most competitive car or the strongest car, but as I said - if you start with a slight disadvantage, it is a long season and it can turn around As usual it is impossible to predict."