Despite having annexed the front row of the grid for the European Grand Prix in Valencia, Red Bull Racing duo Sebastian Vettel and Mark Webber insist that they still haven't got to grips with the team's version of the F-duct.

The Milton Keynes-based team headed to the Mediterranean port city with observers claiming that the street circuit would not suit the RB6, but proved that the latest developments added to the car were good enough to keep it in the mix for pole position with McLaren, and ahead of Ferrari, Mercedes and Renault.

While the rest of the field attempts to copy the 'blown diffuser' concept that allowed Red Bull to steal a march on its opposition through the first third of the season, Christian Horner's team is similarly trying to get a handle on the F-duct idea that McLaren introduced at the launch of its MP4-25. Although it first tried its system in Turkish GP practice, RBR dropped the concept in order to hone it further, and its return in Valencia appears more successful, with both Vettel and Webber using it throughout the weekend.

"It is good that we are able to put the car on pole and I think our pace is looking good," Vettel claimed, "I think it was a very tough one here, especially as we reintroduced the F-duct and a lot of other things to the car - I think some of the mechanics had maybe one hour or two hours this night to sleep, so it is good to say thank you that way and put the cars on one and two."

Asked whether he had felt a major difference with the system in place, Vettel admitted that he expected that there was still more to come.

"I think it isn't that big probably, but we feel the difference," he confirmed, "We can see how much you can gain with [McLaren]. I think they are using it pretty much to the optimum, but we are just learning every single lap, every run and, yesterday, we were not quite happy. But I think we did another step overnight. Everyone here at the track, and people at the factory, were basically spending all their time in front of the monitors, trying to see how we can fine tune it and make it better.

"I don't want to go into too much detail, but we have it on the car, so we believe it gives us an advantage. Obviously, we see from other teams how much it can be worth - probably around 0.4-0.5secs per lap if you really manage to work well with it and you get the wing settings right and so on. For us, at this stage, I think it is less than this, but it's an advantage."

"It's a very complicated system," team-mate Webber confirmed, "McLaren, we know, have had quite a long period of time with it and teams are trying to close the gap to a point where it's sensible. But we are realistic - we're probably never going to have the system as nicely integrated into the car as McLaren have, because they designed the car with it. So we've had to adapt something a little bit different and try to make the system work.

"We are not losing in the corners with the F-duct, and we're confident the car is behaving well. We're confident it's a bit quicker, so that's why we elected to race it. In Turkey, that was not the case and we had some small problems with it there, which, to be honest, we expected. We're learning. Even this morning in P3, we were trying different specs between the cars to try and get it better. Let's hope for Silverstone and future events we can get it even better."

Putting their cars onto the front row was clearly a fillip for the Red Bull team, which was aware of having been written off by those who did not feel the RB6 would be suited to Valencia.

"People were talking a lot about the last race, and that this would probably be a difficult venue for us, but I think we proved them wrong in Canada and here," Vettel claimed, "I think our pace looks very good - I think we have proven that yesterday and all day today - but we were a bit surprised that the McLarens were struggling yesterday. However, as we have seen, things can change last minute and, in the end, they are not too far away. It will be a tough battle tomorrow, but I think we can win the race and score a lot of points."

Williams also reintroduced its version of the F-duct, but only veteran Rubens Barrichello ran it in qualifying, and so it was a surprise that he was out-gunned by rookie team-mate Nico Hulkenberg. The tall German reported that he had had problems finding the hole in the cockpit that he needed to block with his knee to make the system work effectively.