Ferrari insists it has changed “nothing” with the operation of its engine since the start of the 2019 Formula 1 season.

Recent technical directives issues by the FIA have led to Ferrari’s rivals speculating about how the Scuderia is using its power unit, particularly after its sudden resurgence in form following the summer break.

Ferrari appeared to lose some of its straight-line speed advantage last time out in the United States, with Red Bull’s Max Verstappen suggesting its drop in performance was a direct result of the technical directives.

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But Ferrari team principal Mattia Binotto stressed the team’s lack of competitiveness in Austin was not linked to its engine.

“We didn’t change nothing,” Binotto told Sky.

“All we did was to read carefully the TD’s because with a new technical directive it’s important that you understand it. We didn’t change our operations or our way of using the engine since the start of the season.

“We still had an advantage on the straights in Austin,” he added.

“We know since the start of the season that we are lacking downforce and maybe our car is somehow more fast on the straight, so that’s since the very start.

“If you drop your downforce you get some more speed but you reduce obviously what your speed is in the cornering, and our car is not as good as the others in cornering, that’s why at maximum downforce circuits like Hungary, we are lacking speed.

“But we have an advantage on the straights because we are running such a low downforce configuration.”

Ferrari has enjoyed a stronger showing so far in Brazil, with Sebastian Vettel missing out on pole position to Verstappen by 0.123s, while its competitiveness on the straights seems to have returned.

Asked if the FIA is satisfied that Ferrari has complied with the regulations, head of single-seater operations Nicholas Tombazis replied: “Yes we are happy about people complying.

“We track people all the time and the truth is that we should not be happy be completely, meaning we need to keep tracking. We can’t always just say everything is fine because that means we stop working.

“So we check all the cars all the time in as much detail as we can and whenever we have any doubts we ask the teams question.

“If we had any evidence of anybody cheating we would have reported it to the stewards and they would have been promptly disqualified or whatever.”