Horner: Red Bull's best is yet to come

Sebastian Vettel earned the Milton Keynes-based team its first slot at the front of the grid in Shanghai and, with the RB5 now being reworked so a double-decker diffuser can be fitted in the next few races, Horner is bullish about how much more Red Bull can deliver in 2009.

"We've known through winter testing and what we've seen in the races so far that we've got a good car that is not fully optimised under the now clear regulations," Horner told AUTOSPORT. "We know we have a lot more to come."

Red Bull's technical chief Adrian Newey has stayed back at base this weekend to work on the RB5 improvements, and Horner feels upbeat that if the car is quick now without the diffuser then it should be even better when it is added.

"I think Adrian has demonstrated previously that when there has been a big regulation change, he has been at his most creative," he explained. "He has come up with a fantastic car, together with his fantastic team, and the decision to go late with the car was a risk but it was a calculated risk that worked well for us.

"Had it not been for the uncertainty over the double diffusers you can wonder where we would be. Take those diffuser cars out of the equation and then we are looking very strong. So, the positive aspect is we have that to look forward to, but we have to bring it to the car as quickly and as timely as possible, and without compromising other aspects of a car that is obviously very quick."

Although Vettel took pole position, with Mark Webber two places further back on the grid, Horner remains cautious about his team's chances of defeating Brawn GP in Shanghai.

"I think that the Brawn GP is still ultimately the quickest car," he said. "But saying that, Sebastian's Q2 performance was stunning, and Mark's for that matter. We think we are very close to them, but there is an advantage from the diffusers.

"You've seen Renault's quantum leap with them bolting on their diffuser this weekend, so for sure there is performance to be gained. Adrian and his team are working hard on our own interpretation of it but it has to be integrated. It is not just a bolt on component - it has to be fully integrated into the car."