Mercedes duo left without engine boost mode in qualifying

In the wake of Hamilton's blow-up at Sepang last weekend, Mercedes elected to change running parameters in Japan, a move which has included running a different specification of oil and less aggressive engine modes.

The lack of the qualifying boost mode – which is believed to be worth around three tenths of a second in qualifying – could explain why Ferrari was able to get within three tenths of a second of Mercedes at Suzuka on Saturday afternoon.

Mercedes boss Toto Wolff said that the impact of the actions Mercedes had taken was in clear evidence in qualifying, but he was hopeful it would not slow his drivers down too much in the race.

"We have put certain safety measures in place to maybe not run it as spicy as we could," explained Wolff. "But we don't know, as a fact, that this can protect the engine more.

"It also has an effect on laptime during the race, although the race laptime deficit is not as large as the qualifying deficit."

Wolff hoped that the action taken would give Mercedes enough room to be able to come up with a definitive answer as to why Hamilton's failure occurred.

"What we had in Malaysia was a worst case for us as we don't want to interfere in the drivers' championship with a car stopping," he said.

"This is a mechanical sport but it is still something we try to avoid as much as we can. Within a week you are not able to properly assess all the root causes of the problem.

"We have tried to contain it with several measures, which I can't really comment on. But it doesn't give us an ultimate guarantee and relief that we are safe for tomorrow. So it's not an easy situation."

No answers

Wolff said investigations at Mercedes' Brixworth headquarters were ongoing, as power unit chief Andy Cowell worked flat out to deliver an answer about what happened last weekend.

"We get a substantial presentation every day on where they are with the analysis of the power unit, and it's in pieces and all the bits are analysed," added Wolff. "We've been looking at a different engine from the same build to try to find a common denominator.

"There are certain avenues we are pursuing at the moment that look interesting in terms of finding the root cause, but obviously it's only three days since they had the engine.

"So he [Cowell] is flat out. I get emails at the weirdest hours of the day UK time from him. The group around him are working flat out."

Customer impact

Williams, which missed out on getting through to Q3 at the Japanese GP, admitted that it had made changes for this weekend – although engine modes were not hurt too much.

Technical chief Pat Symonds said: "We were planning to use new engines here and we are not using them. We are keeping the old engines.

"We have had to change oils – we haven't had too much of a worry on modes. But until it is fully explained – it is partially explained – what happened with Hamilton's engine, we need to keep a little bit of a lid on things."