Hamilton: Early design shift to 2018 could sway F1 title fight

There has been little to choose between the two teams all season and there are still eight grands prix to go in the 2017 F1 championship race.

But Hamilton warned Mercedes cannot afford to take its eye off 2018 preparations.

"In terms of rate of development we are as strong as anyone," he said.

"But there's a real balance of how much you apply to next year's car.

"We don't want to be the last one to start next year's car.

"So I think that's really where the race is: trying to figure out how much time you spend on continuing to develop this car to get the job done, and to then get the job done for next year.

"That's a battle that Ferrari and us will be having mentally, and within the team.

"But I hope we have more to come, and we need more to come in order to win this thing, for sure."

Though Hamilton reduced Sebastian Vettel's championship lead to seven points in last weekend's Belgian GP, the Ferrari was on his tail throughout. Hamilton believes "that's how it's going to be" until the Abu Dhabi finale at the end of November.

He anticipates a last-round decider and thinks any single reliability problem or shift in performance could swing the result.

"It's going right down to the wire," Hamilton said.

"And I think it can come down to reliability, it can come down to that shift in the pendulum, shifting just that millimetre of performance either way, and then down to us and consistency."