Daimler chairman and head of Mercedes Dieter Zetsche insists Red Bull “never formally asked” to be supplied with power units by the German constructor.
The energy drinks giant sought to ditch its Renault supply last year amidst recurrent engine reliability and performance issues for the French manufacturer. Looking for a replacement, Red Bull tested the waters with Mercedes in order to secure its dominant PU106B unit.
But while motorsport boss Toto Wolff initially said he was open to such deal, his company ultimately ruled out against powering a direct rival outfit. The decision even surprised F1 commercial rights boss Bernie Ecclestone, who thought an agreement had been reached.
Asked by Italian publication La Gazzetta dello Sport on the reason behind such refusal, Zetsche said:
“They never formally asked us for them. There were discussions but there was never an official request.”
Red Bull then went on to try its luck with both Ferrari and Honda, but to no avail. The Milton Keynes-based team will thus carry on using Renault power units in 2016, though these will be branded after new main sponsor TAG Heuer.
Meanwhile, junior squad Toro Rosso returns to the Ferrari fold, with the Faenza outfit set to race year-old engines from Maranello.