Honda scored its first podium of the hybrid era in Australia when Red Bull Racing's Max Verstappen finished third, having overtaken Sebastian Vettel's Ferrari at one point.

"Without doubt, the Red Bulls have a much better power unit this year," said Hamilton. "I think their engine performance is very, very close.

"I believe it's within 10bhp or something of the top cars.

"If you look at their GPS speed on the straights, they're pretty much just as quick as us.

"That's a great start for them and I really hope the reliability's strong for them so they can be really in the fight."

Asked whether Ferrari or Red Bull would be the main challengers to Mercedes in Bahrain, he said: "They were both really strong here last year and Red Bull look like they're really stepping up, so I'm really excited to see."

Hamilton says that Mercedes has made good progress with the W10, but admitted that the team was "fortunate" to find a competitive set-up window.

"We're still learning about it. As we mentioned in testing it really wasn't great to start off with. But we found a window in which it works a lot better.

"We were very, very fortunate to come across that. If we hadn't discovered that in testing, we probably wouldn't have had the same results we did in the first race.

"That was really hard work from everyone collectively. It is a better car but it's not perfect, there are still areas we are working on. But it's a really great platform for us moving forward.

"We do understand the car a lot better particularly from testing, the positive two days, and obviously the race weekend. Now we're moving in a really positive direction."

However, Hamilton says it's too early to see the real pattern of how the three top cars compare.

"Every track offers something different. The last track was very similar to Barcelona in the sense of we use maximum downforce, this is different again as it's very hot here and brings different characteristics.

"I don't feel like any of these races that we have coming up show one similarity. They are all different in their own ways and it takes several races to fully understand where everyone stands, whether a car works on every circuit you can't tell from two. It takes a few races at least."