Red Bull happy with 2008 progress

"In general, we have made a significant step forward from last year, both in performance and also in reliability," said Horner, whose team are currently in fifth place in the standings.

"The battle to finish fourth in the championship seems every bit as intense as the one to win it, with our major rivals being Renault, Toyota, Williams and, on occasion Honda.

"We have seen over the last three or four races that we have been very competitive when compared to the works Renault team and Mark (Webber) and Fernando (Alonso) have had some good races."

Red Bull have scored ten points in the first five races of the season and have regularly been in the top eight in all grands prix so far.

Australian Webber already has more points than in all of 2007.

Webber, whose team was last year plagued by reliability problems, has finished all races except the season opener, where he was involved in a crash at the start.

Horner said the team have taken several measures to improve their reliability.

"Reliability is always important, but the new regulations regarding engine and gearbox life make that even more of a factor this year," Horner added. "Good reliability usually comes from good design and last year we suffered because the car was such a complete change to anything this team had seen previously.

"Since then, we have strengthened the group in several areas, appointed new project managers and reliability has been one of our main focuses over the winter. So far, touch wood, we are one of the few teams with a one hundred percent mechanical reliability record.

"The gearbox was our Achilles heel last year and we gave away a lot of points because of that. Hats off to the whole transmission group who have done an exceptional job with the four race gearbox."

The team's technical chief Adrian Newey also said their RB4 car is so far living up to their expectations, but he admits there is still room for improvement.

"Generally, we are reasonably happy that the car has lived up to our expectations," he said. "One area where the car is struggling a little bit is in terms of traction and we are working hard on finding out why. Other than that, the general package is performing much as we had hoped for.

"In terms of aerodynamics, we are also on target. Last year we struggled with the correlation between wind tunnel figures and what we saw on track. This year has been much better on that front. There are still some differences we would like to eliminate, but they are much less marked than last year."