Red Bull reveal 2011 car

Germany's Sebastian Vettel, the sport's youngest champion at 23-years-old, and Australian team mate Mark Webber pulled the wraps off before the first test session of the year at the Valencia circuit.

Had they produced a pot of paint and daubed a target on the side of the gleaming new beauty, it would have been entirely understandable.

As Vettel said afterwards, the hunters have become the hunted with a focus now on defending the precious spoils - the drivers' and constructors' crowns - they took for the first time last year.

"It will be a tough battle and a long, hard fight," said the German, looking ahead to an unprecedented 20 race season that starts in Bahrain on March 13.

"I think we need to focus again and motivation is not a problem.

"It is a difficult situation we are in now, probably more difficult than we were in last year where we just said 'okay, let's go for the title'," he added.

"This year is a different story. We want to try to defend it but we have to develop from how good we were last year. Otherwise we do a step back and the others pass us.

"If we just approach now saying 'okay let's do the same as last year' we would not move forward."

Team principal Christian Horner said the title double last season had settled the Renault-engined team, raised expectations and boosted confidence without arrogance.

"I am confident that over the course of the season we are well equipped," he added.

Designer and technical head Adrian Newey, who has now masterminded title winning cars for three separate teams after stints at Williams and McLaren, could be excused some trepidation as his latest creation was unveiled.

McLaren, Red Bull's closest rivals last year, will not have their new car on track for another 10 days - taking a leaf out of Red Bull's 2010 book.

Until the Woking-based team starts testing, there will be a lingering concern that they could have something special up their sleeve or have detected a loophole to exploit.

"It's always the balance of research time versus development time, and that's both from the performance and reliability point of view," said Newey, who owned up to taking a quick peek at the new Ferrari on Monday night.

"I was keen to get the car out for the first test this year because of the change in tyres. I want us to learn about the Pirellis as quickly as possible. And therefore give us the maximum amount of time to adapt the car if necessary.

"I think it's one of the beauties and great things about Formula One that there is always the possibility that somebody else will come out with a clever idea that the rest of us haven't thought of," he said.

"I think it's essential that should be part of Formula One... in that sense it's a period of nervousness for us but also a period of excitement."

Pirelli have replaced Bridgestone as sole tyre supplier this year while the front-end teams will also have KERS (kinetic energy recovery systems), which give a brief power boost at the push of a button, back on their cars.