Ferrari has rejected suggestions that a new FIA-mandated sensor on the SF71H has affected the performance of the team's car in recent races.
Earlier in the season the team had appeared to finally get the upper hand over their Mercedes rivals in terms of the straight-line speed and performance of its power units.
But in recent outings the Ferrari has been on the backfoot again, leading to suggestions that it's been forced to stop using a key technical breakthrough that had boosted the power of its hybrid engine.
Unlike other manufacturers, Ferrari has split its battery in two rather than treating it as a single unit.
That's perfectly within the rules, but other teams complained that Ferrari had been able to use this set-up to circumvent the FIA's monitoring of the battery's power output and thereby gain an advantage on the track.
An investigation by the governing body earlier in the season found no wrong-doing by Ferrari. However, it's now emerged that the FIA stipulated that a new sensor should be introduced to the power unit to simplify the situation.
"Our battery layout, it's quite complex," Ferrari boss Maurizio Arrivabene told RTL on Friday in Japan.
"We agreed with the request that we had from the FIA to work together with them and to facilitate their work, and we add a second sensor," he continued. "But it doesn't change in any case the performance of our car.
"Nothing to do with the speed in the straights," he continued. "In Singapore and in Russia, we were quicker. We were ahead in Singapore, and as I said before in Russia we were nearly like our main competitors."
Arrivabene was also unhappy at how the existence of the second sensor had been made public, after it was initially disclosed in reports from Auto Motor und Sport.
"I think it's strange that everybody knows about the second sensor," he said. "Our battery is quite complex, but it's also an intellectual property of Ferrari.
"I hope that because everybody knows about the second sensor, in future, everybody, they're not going to be informed about our project," he warned. "That could be a serious matter."
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