Lewis Hamilton has said that he headed into Formula 1's summer break aware that his lead in the world championship might not last for long.

Many pundits are predicting that F1's reigning champion now looks set for a third consecutive title, having raced to a 19-point lead over teammate Nico Rosberg at Hockenheim.

Yet while Rosberg is on schedule with his engine usage in 2016, Hamilton said he is aware that he will need to use a sixth Mercedes V6 this year, thereby incurring a grid penalty.

There is even speculation that Mercedes will make use of the overtaking opportunities at the forthcoming Spa or Monza rounds by 'doubling up' with a seventh new engine for Hamilton as well, putting him effectively last on the grid.

"I'm conscious that there's going to be at least one more race where I'm further behind and I don't know how much I'm going to be able to limit the damage," said the Briton.

"Now, the Red Bulls have picked up their pace and it might be difficult to get past them, to even get into the top five. I'm conscious of that."

He said that those worries mean he did not head into the August break thinking he was the clear championship leader.

"It's still not enough because I'm not a race win ahead yet," said the triple world champion. "I hope I'll be able to get a race win ahead and then I'll feel like I am ahead."

The championship resumes on August 28 in Belgium.