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Kubica set fastest time seen so far in winter testing on the final day in Valencia Pic:Getty

The team had produced a self-proclaimed "brave" design concept over the winter and in Spain they revealed the so-far unique approach of having the exhausts exit at the front of the sidepods either side of the driver.

Robert Kubica went on to show it was not simply style over substance by scorching to the fastest time seen so far in winter testing on the final day.

The Pole's time was 0.163 seconds quicker than Alonso and 0.625 secs ahead of Vettel's best.

F1 insiders calculate those three leading times were all set on similar levels of fuel, even though Kubica and Alonso set their times on a five-lap run while Vettel's best came over 10 laps.

Those runs were not in qualifying trim and so all three could, in theory, have gone even faster.

Kubica also encouragingly showed good pace over a 25-lap run with most tours in the 1:16s bracket, while Mark Webber exhibited consistent pace for Red Bull on Thursday in a 20-lap run which mainly consisted of 1:15s.

Kubica, Alonso and Vettel may have tantalised the top of the timesheets but in testing headline lap times don't tell the whole story.

Valencia was the first opportunity for teams to trial their technical updates for the 2011 season.

Yet another raft of rule changes - the return of the Kers energy boost system, the introduction of a moveable rear wing to aid overtaking and the removal of the double diffuser and F-duct aerodynamic aid - has meant a major re-think for design departments.

On top of that there is the problem of understanding how to tease performance out of the Italian Pirelli tyres, back in F1 for the first time since 1991 as single supplier in place of Bridgestone.

It is, in fact, the tyres that have leapt to the top of the teams' concerns about what fortunes lie ahead.

"Tyres are more of an unknown," commented Ferrari technical director Aldo Costa, throwing back an espresso in a single gulp.

"It is a very, very big job to develop the car around the tyres because they have a lot of implications on the car consistency and performance."

Even Red Bull's seemingly unflappable design guru Adrian Newey described it as "difficult to design for the Pirellis".

To a man, the drivers agreed that the Pirellis "went off" - reduced significantly in grip - much quicker than they were used to.

McLaren's Lewis Hamilton said the new rubber did not have "as much grip as the Bridgestones" and was "harder to control over a longer stint".

Kubica agreed with that assessment, adding: "That is why I think the tyres will play a crucial role. You may have to adapt your car set-up, or make the tyres last longer, or work better - that can make a big difference."

Pirelli has been asked to deliberately design less durable tyres in the hope that this will spice up the racing.

The company's motorsport director Paul Hembery batted away the drivers' disappointments.

"There will be no developments [to tyres] made following this test," he explained. "The teams now have to work out how to get the best out of the tyres."

Eight teams rolled out the first interpretations of their 2011 challengers in the Valencia sunshine, while McLaren, Force India, Virgin and Hispania ran last year's cars.

The main priority for teams with the fledging class of 2011 cars was to find out if the new parts were reliable. Only much later will it become clear how much, if any, performance they have added to the car.

"Looking only to our car, yes we are very happy," Costa said. "It needs to be a very balanced approach to be a fast and winning car.

"About the competitors, it's very difficult to understand where they are because it is difficult to see if they are using Kers or not, the rear wing or not, what kind of tyre they are using, how much fuel..."

The teams fiercely protected their secrets behind towering screens, guarded garage doors and under billowing sheaths. When Felipe Massa dramatically stopped on track on Thursday, crimson-clad Ferrari employees remarkably managed to hang a concealing cover underneath the car.

As always, the teams were keeping their cards close to their chest about the specifics of their programmes.

Most teams testing the 2011 cars had Kers installed for the majority of the running, even if they weren't actually powering it up.

Ferrari, Renault and Red Bull ran smoothly while Mercedes reported their Kers system was behind some of their teething problems, even though Mercedes had the most reliable when it was last deployed in 2009.

"We've got some areas that were getting a little bit too hot," Mercedes boss Ross Brawn said coolly.

The moveable rear wings also seemed to be a relatively trouble-free addition. The concept is such an integral part of the design rules that even if the wings played a passive role in testing they were still worth having on the car.

It will be up to the drivers to master the devices and with more buttons to press on the steering wheel that may not be quite so straightforward.

"In terms of all the other things we are operating from the cockpit, last year we had quite a bit to do and that was quite a challenge," Webber said.

"It's no big surprise to us that we might have to learn some new techniques this year but as long as you can still watch the road, that's the most important thing."

In less than a week, round two of testing begins in Jerez, where McLaren will also introduce their new challenger - which is being unveiled on Friday - to the pack.

Teams vying to rein in Red Bull talked with a beguiling mix of mystery and confidence about unspecified new developments in the pipeline.

But the clock is already ticking and there are just 12 days of testing left before the teams face up to reality in Bahrain's opening grand prix.