Red Bull a major threat to Mercedes at Hungarian GP - Toto Wolff

Over the course of the season Red Bull has steadily become Mercedes' biggest rival, with Max Verstappen winning in Spain - following the first-lap wipeout involving Lewis Hamilton and Nico Rosberg - and then taking second-place finishes in Austria and Britain.

The Hungaroring's tight, twisty characteristics have generally favoured Red Bull in the past, with Ricciardo winning in 2014, while the Australian was third last year behind runner-up team-mate Daniil Kvyat.

With it being the only circuit on which Mercedes has yet to win in the V6 hybrid era, Wolff said: "We face a very different challenge in Budapest.

"This circuit has not been kind to us over the past two years, and it plays to the strengths of our rivals.

"The Red Bull, for example, is a car that functions well where high drag isn't penalised as much as at other types of circuit.

"So in wet conditions and at low-speed circuits such as the Hungaroring, they are a major threat. We will need to be flawless to come out on top at this track."

Though the Hungaroring was the scene of Hamilton's first win for Mercedes in 2013, he has had messy weekends there since.

Third place in 2014 came only after a fire in qualifying and a team orders row in the race, while last year he went off on the first lap and later earned a penalty for colliding with Ricciardo.

But he said he is "buzzing" heading to Budapest this year after four wins in the last five GPs.

"I'm feeling fresh, feeling powerful and feeling confident heading to Hungary," said Hamilton.

"It's a track that for some reason has always suited my style and I have incredible support there.

"The past couple of years I haven't had the smoothest weekends in Budapest, of course, but I know I've got the pace, so I'm gunning to turn that around this time."

ROSBERG DISAPPOINTED WITH SILVERSTONE PENALTY

Rosberg, meanwhile, has expressed his frustration at losing second-place at the British GP when penalised for breaking the regulations regarding radio transmissions.

Having dropped to third behind Verstappen with the penalty, Rosberg's championship lead over Silverstone winner Hamilton is down to just one point.

"Silverstone was a good weekend except for the loss of position following the stewards' decision after the race," said Rosberg.

"It was disappointing to lose a hard-fought and deserved second position in such a way, but we have accepted the decision and now I have to look forward with positivity.

"I am leading the world championship coming up to the halfway point of the season and there's still a long way to go.

"The battle is on with Lewis, and I'm feeling great in myself and great in the car, so bring it on! I can't wait for the next battle between us in Budapest."