Pirelli Motorsport Director Paul Hembery has hinted the true form of this year's F1 contenders won't be witnessed until the opening rounds as teams attempt not to give too much away to rivals in pre-season testing.

F1 will undergo a major technical overhaul in 2017 in an effort to readdress the balance between engine and chassis superiority, with aerodynamic tweaks and an increase in tyre size destined to raise corner speeds and improve lap times by upwards of five seconds.

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Though teams will continue to keep their technical details well-guarded until launch dates loom towards the end of February, Hembery doesn't believe the ensuing eight days of pre-season testing will give everything away either as packages are honed up to the first race in Australia.

"I think we will get an idea in Barcelona, but I think there will be a lot of sandbagging and hiding in Barcelona," he told Crash.net. "I don't think anyone will show their hand because the aero package is so different that I am sure there will be a few dummy runs for the teams that feel confident in their simulations. They don't want to give any team a one month head up to what rolls out of the garage in Melbourne."

Indeed, with only limited testing available to teams prior to the Australian Grand Prix, Hembery admits Pirelli will also need to conduct some real-time tweaking once the season is underway as Barcelona in February and March won't provide the data it ideally needs.

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"We have managed to perform a lot of development work on the mule cars but of course those cars are four or five seconds slower than the cars we are going to see in Melbourne," he continued. "So there is some verification work to do, some of that we will do in Barcelona but the reality is - due to weather conditions - it will be the first races of the season where we truly understand the compounds.

"We have working off the assumption of the data we have been given and in terms of performance of the cars we need to know if the cars match the data we have been given. Maybe less, maybe more but we won't know until we get the data for the race cars. I am quite sure the brilliance of F1 engineers someone has come up with something that nobody had thought about and we will discover new things along the way."

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