Red Bull: Engine legality lockdown ahead of F1 2020 important

Red Bull notably sought clarification from the FIA during the United States Grand Prix over three fuel flow scenarios, which the governing body deemed illegal under the current rules.

The growing engine saga came after Ferrari enjoyed a sizeable power advantage in the second half of 2019 - Ferrari has always maintained its engine is legal - and rivals explored potential grey areas in the rules that they feared were being exploited.

While the FIA directives have not forced power unit changes for Ferrari or its rivals, the FIA directives have been welcomed by teams.

Red Bull's engine partner Honda is still catching up to Ferrari and Mercedes, and Red Bull team principal Christian Horner believes the directives are essential.

"The power unit aspect of the car is an incredibly complex piece of kit," Horner told Autosport. "And I think that the FIA don't have the expertise that the teams have developed.

"I think what has been clarified is a lockdown in various areas, which is focused on what's happening going forward rather than looking behind us.

"And for us, what was enormously important was to have absolute clarity going into the 2020 season."

Asked if he felt that grey areas in the rules had been exploited, Horner said: "We were very grateful for the clarification that came. That's for the benefit of everybody."

One of the changes that have emerged from the FIA's clarification process is the mandatory fitting of a second fuel flow sensor for 2020.

This came amid speculation that some teams had found a way of tricking the measurement processes of the old single sensor to allow an additional flow of fuel to be undetected.

Speaking at the end of last year, Ferrari team principal Mattia Binotto said his outfit had proven the legality of its power unit.

"If I look at the whole season, we have been one of the most checked teams, that was before or after the technical directives," he said.

"And when you got a performance advantage, and certainly we got it during the whole season, we have been the most checked.

"Being checked, I think it's normal, it is somehow good because through the checks you are proving your legality.

"After the technical directives, the number of checks on our cars have multiplied. The reviews have been shown to FIA, the details have been discussed.

"So whatever could have been done through collaboration with the FIA has been done.

"We have never changed our way of operating the engine for the last part of the season, showing that somehow our power unit has full legality.

"Otherwise, had that not been the case, if there would have been any non-legality, it would have come out at the very first check."