Lewis Hamilton says nothing more than hard work is behind his improved starts, crucial in his 19-point advantage over Mercedes team-mate Nico Rosberg at Formula One's summer shutdown.

Rosberg won the first four races of 2016, besting pole-sitter Hamilton off the line in Australia and Bahrain as the reigning drivers' champion was let down by his launch.

However, Hamilton now has a quartet of consecutive wins behind him and it is he who has had the better of the Silver Arrows' starts - winning in Hungary and Germany despite Rosberg taking Saturday honours.

"It's kind of the luck of the draw. We have worked very, very hard," Hamilton said after Sunday's dominant victory at the Hockenheimring. 

"Obviously I have a guy that I'm working with very, very closely and it's been an up-and-down season and it's not his fault or not my fault, it's just the way these new clutch-regs [regulations] are and how sensitive the clutches are. 

"I think we've worked, and worked and worked, and just consistency and really trying to be precise with the whole procedure. 

"And I think today the procedure, the last two races, the procedure's been spot-on, pretty much. Today was definitely the best one I would say. Yeah, it's just a work in progress."

Hamilton could choose to take a new power unit at Spa in four weeks' time, the overtake-friendly track could benefit him as he takes a 10, or possibly even 20-place penalty for using a sixth engine element of the season.

"Hopefully I've saved enough of my engine today hoping that I would be able to use it at the next race," he explained. 

"It will either be the next race or Monza, because I'm going to run out of engines soon."