Hamilton: Australian Grand Prix update could put Red Bull top in F1

Like Mercedes, Red Bull did not chase headline lap times in pre-season testing testing at Barcelona, but was buoyed by its running over the two weeks.

It impressed its rivals too, with Mercedes technical director James Allison suggesting Red Bull was potentially the main threat to his team's dominance and Hamilton anticipating a "real challenge".

Speaking to the media at an event for Mercedes' title sponsor Petronas, the reigning world champion went even further, suggesting Red Bull could be the team to beat at the start of 2018.

Daniel Ricciardo said at Barcelona that the RB14 would undergo changes between testing and the Australian Grand Prix, with new "go-fast" parts set to be added to the car.

"I think this year is going to be exciting, because last year there was a big difference between teams in the beginning, and then they got closer," he said.

"But this year it starts this close and then it's going to overlap, and separate, and overlap during the year, as people are developing.

"Because we don't bring upgrades at the same time, I think Red Bull will bring something at the first race, which will be interesting to see.

"I think Red Bull are the fastest at the moment, potentially.

"They have some sort of upgrade coming, of some magnitude, two-to-four tenths or something like that - that's what I heard."

Hamilton added: "They have generally a slightly different philosophy, they always build a car that has lots of downforce.

"Their maximum downforce has always been more than everyone else's.

"But that doesn't work always everywhere. Some places where you have longer straights - because they're very slow on the straights, normally, but they're fast through the corners. This advantage shifts through the year.

"I'm super confident in my team and the work they've done, I just think it's going to be close."

Hamilton's team-mate Valtteri Bottas said he was not sure whether Red Bull or Ferrari posed the bigger threat to Mercedes' title defence.

"I think they both look strong," he said. "It depends on the early-season development. I wouldn't underestimate either of those.

"My feeling is it's going to be a three-team battle. That's how we're going to at least start the year."