Lewis Hamilton says Red Bull has “a much better power unit” after switching to Honda this season and is likely to be a bigger threat at the Bahrain Grand Prix.

Red Bull won four races in 2018 but split from Renault after 12 seasons, having been unable to consistently fight for victories since the introduction of the V6 power units in 2014. Moving to Honda, Red Bull was strong in Melbourne as Max Verstappen pushed Hamilton close in the final laps for second place, and the defending champion is wary both Red Bull and Ferrari could be threats this weekend in Bahrain.

“They were both really strong here last year and Red Bull look like they’re really stepping it up,” Hamilton said. “I’m really hoping it’s closer this weekend. I know some people think we were sandbagging or whatever in testing but, honestly, we came into the first race thinking it would be a lot closer than that and from the information I had we were behind.

“Coming into this weekend we had the pleasant surprise of being faster in the last race but it could absolutely change here. Maybe the tires weren’t working for (others) or something in the last race, maybe it will work here, so I’m just as excited as you are to see how that pans out.

“Without doubt the Red Bulls have a much better power unit this year. Their engine performance is very, very close — I think it’s within 10 horsepower or something within the top cars, so if you look at their GPS speed on the straights they’re pretty much just as quick as us in some places. That’s a great start for them and I just really hope the reliability is good for them so they can stay in the fight.”

Ferrari struggled in Australia despite looking quick in testing, and while Hamilton predicts the Scuderia will improve in Bahrain, he says a true picture of the competitive order will take a number of races to emerge.

“I assume that they’re working hard on understanding where it perhaps went wrong, but I fully anticipate that race on race, they’ll be stronger. They’re very strong here most years, so I anticipate they will be a lot closer this weekend. But again, that’s just a guess.

“I think every track offers something different. The last track was very similar to Barcelona in terms of how much you use maximum downforce. This is different again in the sense that it’s very hot here — it brings different characteristics.

“I don’t feel any of these races that we have coming up show one singularity that’s different. I think they’re all different in their own ways, and as I’ve always said in the past, it takes several races to fully understand where everyone stands, whether a car works good on every circuit — you can’t tell from two. It takes a few races at least.”