"It’s frustrating that we are in the situation we are," said Horner. "We’ve had a lot of success with Renault, we’ve won all the races and all the championships we’ve achieved with Renault power. The situation just isn’t improving at the moment. Reliability is unacceptable, performance is unacceptable.
"There needs to be change at Renault, because it can’t continue like this. It’s not good for Renault, it’s not good for Red Bull. We need to work together as partners â there will not be another engine in the back of the car next year, we want to be competitive, we want to run at the front, and these kinds of issues can’t and shouldn’t happen.
"Something needs to happen, because whatever’s being done there is not working at the moment. It’s not our business, it’s not our responsibility, we’re the end user. It’s just frustrating that the product is just not working at the moment.
"It’s no surprise that there are eight Mercedes cars in the top 10. We haven’t been competitive this weekend, eighth was the optimum that we could achieve, and it’s frustrating that we’re nearing the halfway point in the season and the situation hasn’t really improved from Melbourne."
Asked about suggestions from Helmut Marko that Red Bull could pursue its own engine project he said: "It’s highly improbable. First of all we need to see what the plans of Renault are. Obviously a team like Red Bull isn’t short of choices, but we want to make sure that we’re competitive for the long term. Obviously designing and manufacturing our own engine currently isn’t part of our plan."
Meanwhile, Horner confirmed that Vettel retired from the race in order to preserve his equipment for future use.
"On the first lap, by the time he got up to Turn 2, the engine lost all drive. It looks like an electrical issue, there was no throttle response whatsoever. Obviously he lost a lap while there were plenty of resets going on and we were trying to establish what the issue was. The engine came back into life, he got going, at which point he was a lap and a half down. We kept going and then after some front wing damage with Gutierrez, following that it didn’t really make sense to go any further."