Red Bull team principal Christian Horner says the FIA’s technical directive on power units will ensure teams do not break the rules on how they are to be used.

The was widely believed to be aimed at Ferrari, who have had consistently strong performances on power-sensitive tracks this year.

However Ferrari rejected suggestions from Red Bull driver Max Verstappen that the issuing of the directive was connected to their sub-par performance in Austin, where no Ferrari finished on the podium for the first time since May.

Horner said he was satisfied with the directive issued by the FIA, which came in response to a query from Red Bull.

“The power unit is an incredibly complex piece of machinery, both from a hardware and software perspective,” he said. “The clarifications that we requested were standard stuff that goes backwards and forwards continually between the teams and the FIA. So it’s always good to get clarity before wasting effort.”

“The technical directive was very clear,” he added. “I think it’s not to say anybody was doing anything, but if they were, it would obviously be illegal.”

Horner was asked whether he believed Red Bull’s deficit to Ferrari on the straights had been reduced at the Circuit of the Americas. “It looks a little bit closer in qualifying, I would say,” he replied. “I haven’t seen any data from the race.”

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2019 F1 season