SPIELBERG, Austria - Formula 1 champion Red Bull called for change from engine partner Renault after an "unacceptable" performance in Sunday's 2014 Austrian GP.Quadruple champion Sebastian Vettel retired at Spielberg with an electronics problem, his third did-not-finish this season due to an issue with the new V6 turbo hybrid power unit.TRAILING BEHINDTeam principal Christian Horner told reporters: "The reliability is unacceptable. The performance is unacceptable. There needs to be change at Renault. It can't continue like this. It's not good for Renaul, it's not good for Red Bull."The team won the Drivers' and Constructors' titles for all four previous years with Renault engines; now, June 2014, it is 158 points behind leader Mercedes after eight races.Australian Daniel Ricciardo won the previous race in Canada but was a distant eighth in Austria.RenaultSport F1's deputy managing director Rob White said the French manufacturer, which started 2014 well behind Mercedes on performance, knew what had to be done and progress was being made.White told the Autosport website: "The anxiety that Christian feels, and the frustration he feels after a result that is not at the full potential of the performance of car and power unit, is completely understandable and shared by us."We know what is expected of us and individually and collectively we must buckle down."Horner made it clear that Red Bull would stay with Renault for 2015 season when Honda is due to make its return as partner to McLaren, but he wanted a big improvement.The only other engine manufacturers are Mercedes and Ferrari.Horner said: "We need to work together as partners. There will not be another engine in the back of the car in 2015 but we want to be competitive and we want to run at the front. Something needs to happen because whatever's being done there at the moment isn't working."It's not our business, it's not our responsibility. We're the end user and it's just frustrating that it's not where it needs to be at the moment."Stay with Wheels24 for the 2014 F1 season – fresh reports every day.