Red Bull's triple world champion Sebastian Vettel is struggling to adjust to his new car, according to team boss Christian Horner, as the German sits fifth in the table, 46 points behind leader Nico Rosberg.

Vettel has also been out-raced by teammate Daniel Ricciardo in the last two races and was 20 seconds behind the Australian at the Chinese GP.

"Sebastian's having a tough time at the moment because he hasn't got that feeling from the car that he is looking for," Horner said. "He's tremendously sensitive to certain aspects of the set-up and he's not getting the feedback from the car that he wants.

"The compound effect of that is that he's damaging the tyre more, which is very unusual for Seb, as we've seen since the Pirellis were introduced. That's just the culmination of the issues that he's currently got and as soon as we've worked those out he will be back with a bang."

Rosberg wants more

Meanwhile, Rosberg remains confident that Mercedes can extend its gap at the top of the table at the Spanish Grand Prix which takes place in three weeks.

Mercedes have won all the races this season so far and sit top of the table with 154 points. Ferrari are second with 54.

"We want to go to Barcelona with the biggest step, that's our ambition," Rosberg said, "Barcelona is a chance for us to extend the advantage that we have and that's the approach that we have going to Barcelona, 100%."

Source: Al Jazeera and agencies