Lewis Hamilton says he is surprised how much his old team McLaren is struggling in 2015."When I saw them so lost in Australia, I thought to myself \'How can that be?\'" the reigning world champion sai

Lewis Hamilton says he is surprised how much his old team McLaren is struggling in 2015.

"When I saw them so lost in Australia, I thought to myself 'How can that be?'" the reigning world champion said, referring to the once-great British team.

Having been mentored and sponsored by Ron Dennis throughout his boyhood, Hamilton made his debut for the Woking team in 2007, winning his first title a year later.

Eight years on, the now-superstar Hamilton is dominating formula one with his new team, Mercedes, and speculating that McLaren "underestimated" the challenge of switching to works Honda power.

"When you think of their factory, their history, their potential, (where McLaren is now) seems impossible," Hamilton is quoted by Spain's El Pais newspaper.

"They decided to change the engine and my experience tells me that in F1 it is quite common when challenges are underestimated.

"For example, in 2009 when the double diffuser (introduced by Brawn GP) suddenly came into play, most people underestimated that.

"I love that Mercedes doesn't underestimate anything," Hamilton insisted.

"It made sense that McLaren would not be fighting to win. I am convinced that they will do so again, the question is when."

Struggling with the Woking team in 2015 is Hamilton's first McLaren teammate, Fernando Alonso, who Hamilton says deserves more than his career tally of two titles.

"You make the decisions you make," he said, "but you also need to be in the right place at the right time.

"Michael Schumacher won seven titles but I see Alonso on the same level as him in terms of talent," Hamilton added.

"He (Alonso) made his own decisions but when you look at Ferrari now, how well they are going and you think that he left when he still had a contract, you think 'My god!'" he said.

McLaren had a dismal weekend in Barcelona, including 30 laps for Jenson Button that he described as "the scariest of my life" due to handling problems.

"After today, I don't think I expect points at all this year," the 2009 world champion admitted.

Alonso, meanwhile, almost collected his front jack-man in the pits when his brakes failed.

Five races into his new McLaren adventure, the Spaniard might be forgiven for finally showing some signs of frustration.

"It seems that many people want myself and McLaren to be frustrated," he smiled to Spanish reporters on Sunday.

"The truth is that we were four and a half seconds behind in Australia and now it is two. No team in history has recovered two and a half seconds in such little time.

"Before we were racing alone and now we are racing other teams," said Alonso.

And Alonso says that despite the Barcelona blip, even more progress is looming.

But: "We are a long way off so we need to make double steps, because everyone else is improving during the season too.

"This is a very challenging project, but we are recovering well and we need to keep it up," he added.