Red Bull technical chief Adrian Newey has reflected on the decline of the team's relationship with former engine partner Renault following their initial streak of success in Formula 1 with Sebastian Vettel.Vettel claimed four consecutive World Championships between 2010 and 2013 in the final years of the V8 engine era, with Red Bull and Renault's exploitation of exhaust-blown technology a critical factor in the team's success.However, Red Bull's dominance ended when Renault struggled to adapt to the new V6 hybrid powertrain rules in 2014, and the two parties went their separate ways at the end of 2018 after the relationship became increasingly tense.With Honda power, Red Bull ended an eight-year wait for a title when Max Verstappen clinched the 2021 title, with the team winning their first Drivers' and Constructors' Championship double since 2013 this season as Verstappen and team-mate Sergio Perez won 17 races between them.Lack of progressReflecting on Red Bull's route back to the top from the low of a winless season in 2015, Newey admitted Renault's lack of progress after a poor start to the hybrid era was difficult to deal with.In an interview released by Red Bull, he said: "The championships years of 2010 to 2013 were all with the Renault V8.
We had a great relationship with the engineers at Renault."I think it's fair to say they didn't have the most powerful V8, but it was a product that they tailored to suit our car.
We had some particular requirements, particularly in the way we used the exhaust, and Renault bent over backwards to maximise what we needed from the engine."We then went into the hybrid era, and Renault, in the first year, [didn't] interpret the regulations as well as Mercedes, so we were quite a long