Sebastian Vettel blamed his relative slump to fourth in Sunday's Spanish Grand Prix on Red Bull's inability to manage its tires as well as rivals Ferrari and Lotus.

But the triple world champion insisted he was happy with the potential speed and performance of his car.

The German said: "I think we can be happy with fourth - or at least we have to be. The first three cars were a little too fast for us and in looking after their tires they did a better job today."

He is confident there is no lack of raw pace in the Red Bull.

"If you talk about race distances, then it's a different game," Vettel said. "I think the car is quick enough, but there's something we do to the tires to make them wear more.

"Three people did better today, so we need to catch up. We are not going to the pace of the car, we are going to the pace of the tire."

Vettel added that Red Bull made a strategic mistake by initially trying to pull off a three-stop plan before resorting to four.

"I think we tried to hang on to the three-stop for too long in the race and had to admit towards the end we wouldn't make it," he said.

Mercedes pole-sitter Nico Rosberg meanwhile said he was shocked at how quickly he slipped away from the front of the field, eventually having to settle for sixth.

The German's teammate, Lewis Hamilton, suffered a similar fate - finishing 12th after sharing the front row.

Rosberg's drop down the order began on lap 12, when race winner Fernando Alonso passed him into Turn One in his Ferrari and then he was further demoted by Vettel and Kimi Raikkonen of Lotus.

Rosberg, who finished ninth after starting from pole in Bahrain last month, said: "I didn't expect it to be that tough. I thought we would be in a better position.

(China Daily 05/14/2013 page24)