Mercedes are to run their engines at a lower performance at this weekend's Japanese Grand Prix.

World champion Lewis Hamilton suffered a fiery power-unit failure while he was leading Sunday's Malaysian Grand Prix.

Hamilton's engine had a big-end failure without warning, preceded by a loss of oil pressure at the final corner of the previous lap.

All four Mercedes-powered teams will run with the revised performance parameters.

These include, but are not limited to, a more conservative oil specification.

A planned upgrade for the three customer teams - Force India, Williams and Manor - has been delayed so the team can learn more about Hamilton's engine as it is stripped down at the factory in England, and incorporate any subsequent modifications in future engines.

This weekend, Hamilton will be using the engine he had in Singapore, and team-mate Nico Rosberg the one from Malaysia.

Both men have two new engines to see them through the final five races of the season.

Hamilton was poised to retake the championship lead in Sepang. Instead, Rosberg has a 23-point advantage with a maximum of 125 points still available.

It was the latest in a series of engine failures that have hit Hamilton this year and affected his title campaign.

Mercedes boss Toto Wolff said: "We've talked amongst ourselves and said: 'How is this possible?' But there is no rational explanation or pattern in these failures. If there were, we would resolve it.

"We've had that discussion with him and he understands that we are feeling his pain too.

"Despite his frustration, he has been trying to pick the team up and we admire him even more than ever for that."

Nico Rosberg span at the first corner in Malaysia after being hit by Ferrari's Sebastian Vettel but recovered to finish third
Nico Rosberg spun at the first corner in Malaysia after being hit by Ferrari's Sebastian Vettel but recovered to finish third
Mercedes executive director (technical) Paddy Lowe added: "Malaysia was a bitter pill to swallow. We let Lewis down in a big way. We are continuing to investigate the issue with his engine and are doing everything we can to ensure that it is first understood and then contained for the remainder of the season.

"As it stands, despite the failure of this engine, Lewis now has the same stock of power units as Nico for the remaining five races. So, hopefully there will be no further impact to his programme."

Hamilton said he would not dwell on the "massive disappointment" of Malaysia.

"That's just negative energy," he said. "It's not the lowest point I've had. There have been lower moments, for sure."

This weekend's race, at the challenging Suzuka track, is expected to be affected by intermittent wet weather in the wake of Typhoon Chaba, which disrupted travel in Japan on Wednesday.

Rosberg said: "I feel for Lewis, as I've been there myself and it sucks big time to have all those points taken away from you just like that.

"I haven't been thinking about the points situation all season and I'm not going to start now. I'm here to win races and that's the aim every time."