Renault's engine boss has admitted the French works team was also concerned about the legality of the power unit used by Ferrari last year.

Red Bull and Mercedes made no secret of their suspicions about Ferrari's clear engine advantage mid last season, prompting a round of FIA clampdowns.

"We are very happy about the clarifications that came through," Red Bull team boss Christian Horner is quoted by Germany's Auto Bild.

"Everyone benefits from that."

Renault, however, stayed quiet amid the Ferrari engine legality furore, but the French marque's F1 engine chief Remi Taffin admits there were discussions behind the scenes.

"Quiet is the wrong word," he told Auto Motor und Sport. "We just didn't talk about it in public.

"Our regular enquiries to the FIA were also not made public. But in the case of Ferrari, the teams you mentioned decided differently."

Taffin said there is nothing out of the ordinary about teams making enquiries to the governing FIA about how the rules are being interpreted.

"Sometimes you have an idea that could give you an advantage, but you're not sure whether you are interpreting the rules correctly. So you ask for clarification," he said.

"If the FIA is satisfied with it, we won't make it public. We want to keep the advantage to ourselves."