Sebastian Vettel: Insists no one can be classed as favourites yet

Sebastian Vettel: Never a winter testing less conclusive than 2013

The culmination of the 12-day winter testing period on Sunday at the Circuit de Catalunya continued to provoke even more questions that concrete answers regarding the form book ahead of the first race in Melbourne, with no one seemingly quite sure who is in the most competitive shape, or crucially, to what degree.

Vettel's own Red Bull team remain the favourites heading to Australia but Mercedes' eye-catching late winter surge to the top of the timesheets has suddenly thrust the Brackley team firmly into the spotlight, whereas there are also many unknowns over McLaren, Ferrari and Lotus's true form over both long and short runs.

And while testing timesheets are historically often an unreliable guide at the best of times, Vettel says the high levels of tyre graining experienced by the whole grid during all three winter tests has skewed the picture like never before.

"I think we never had a winter that was less conclusive than this one," the Triple World Champion told Sky Sports News at the end of his on-track preparations for this title defence.

"Tyres last, if anything, one lap - for some people [it] may be different than others depending how much temperature you're able to create - so I think it's impossible to read the pace of the car and therefore to make out the favourites.

"I think it's not that easy but we will know in Australia."

The unpredictable performance teams were finding with Pirelli's softer 2013 tyres, which was first put down to an atypically abrasive surface at Jerez and then generally cool temperatures across the two weeks at Barcelona, meant drivers were often able to get more than one or two consistent timed laps during a stint before the rubber fell away.

Vettel admitted Red Bull found the inconsistency stymied proper set-up comparisons - but did stress that the situation could turn on its head come the expected warmer climes of Melbourne, thus effectively rendering the timesheets of the Spanish winter meaningless.

"It was extremely difficult to read some set-up changes and find the direction with the car because the tyres were simply not good enough," he declared.

"I think the last two days were fairly good in terms of weather - blue skies, sunshine, it wasn't very cold and the asphalt was quite warm - but the tyres were still poor, so we need to see.

"[We will] look into the data between now and Melbourne to understand a little bit more and then we probably know what expects us in Australia and for the beginning of the season - but it could all be different.

"So I think therefore lap times are not important and where we are now on the timesheet is not that important."