Christian Horner has admitted that he is unsure where Red Bull stand compared to its rivals going into the new F1 season, insisting that what has been seen so far in testing will count for little when teams arrive in Australia next week for the season opener.

While pre-season testing for the new RB8 went well on the whole, the final test in Barcelona ended in troubled fashion when a gearbox issue and a off-track trip for Sebastian Vettel left the defending champion with little running behind the wheel of the revised car.

Speaking to Sky Sports, Horner admitted it was difficult to tell exactly what level each team was at based on testing and the differing programmes being run up and down the paddock, with a number of teams set to challenge during the year ahead.

"It's always difficult to say because teams always run different fuel levels in their car," he said. "That obviously masks performance, but we've been relatively happy with our pre-season testing.

"We've ticked most of the boxes we wanted to and it's only when we get to Melbourne and the fuel comes out of the car what the pecking order is for the start of the season. We know McLaren are looking strong and Mercedes look like they've made a step forward, Ferrari - it would be foolish of us to dismiss them - so I think we're set for a really exciting season."

In a further interview with BBC Radio 5 Live, Horner confirmed that the revised car seen on the final two days of running in Barcelona would be taken to Australia for the opening race of the year.

"It's amazing how these things get construed," he said. "We introduced another car in Barcelona because it had an update package which was always the plan. All the major teams introduced quite a major update prior to the first race and you leave it late because you don't want the concepts to be copied by your competitors.

"Those upgrades seem to be working okay and they'll certainly be on the car in Australia in ten days' time."