Questions surround Red Bull before Melbourne

Just a week before Formula 1 starts buzzing again in Melbourne, Red Bull Racing is the subject of a bit of speculation regarding its pre-season form.

The Milton Keynes-based outfit ran by far less miles that either Mercedes or Ferrari in Barcelona and achieved only the fifth fastest lap overall.

The team's performance even prompted Sebastian Vettel to tease his former team: "Have they just put the 2016 car on wide tyres?".

Asked whether his team will perhaps "surprise" with its Melbourne car, Christian Horner's response only provided further perplexity.

"You can count on it, although it might be a different surprise to what you imagine," he said.

• Red Bull expecting 'intense' build-up to Melbourne

Another theory is that Red Bull's development programme in Spain was hindered by reliability issues with the new Renault engine.

This fact was compounded by Toro Rosso and the works Renault outfit which were both hit with an apparent ERS problem affecting the French power unit.

Helmut Marko also underlined that Red Bull's reliability worries.

"We've had several problems with the MGU-K," he told Speed Week.

"We were told that it would be fixed for the second test but it was not."

But the Austrian also admits that the team's RB13 is not perfect.

"Sometimes we don't get the tyres in the correct temperature window, and we don't fully understand why."

Only competitive running in Australia at the end of next week will unveil Red Bull Racing's true state of affairs.

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