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."