Renault's F1 engine hurting Red Bull more than Toro Rosso - Horner

The Red Bull team principal believes that the characteristics of the engine are having a compound negative effect on the RB11.

This explains why Red Bull was only just ahead of its b-team during the Australian Grand Prix weekend.

Red Bull: Renault "in a bit of a mess"

The lead Red Bull of Daniel Ricciardo less than two-tenths of a second quicker than Carlos Sainz Jr's Toro Rosso in qualifying, and although the Spaniard was 58 seconds behind in the race, more than half of that deficit was a result of a disastrous pitstop.

"They are struggling the same amount," said Horner of Toro Rosso's battle with the Renault engine's weaknesses.

"It's just having a more dramatic on our car, at the end of the day.

"I think it [the engine problems] masks so many things regarding corner entry and corner exit, degradation and slip control of the tyre.

"You are not able to drive the car properly, so you start moving the brake balance around to try to compensate, so you are so far away from the optimum.

"Then you start to lose temperature in the brakes and then the tyres are not working as it should.

"It's a spiralling effect."

But Toro Rosso has also struggled with the same problems, with Sainz admitting after qualifying that the engine was a major weakness in its battle with the Mercedes-powered Lotus squad.

"I don't want to criticise and say too much in this first race because obviously there are a lot of races to improve and go forward in," he said.

"But at the moment I would say our biggest deficit compared with the Lotus is we are down on speed.

"We are much better in the corners, but much worse than them on the straights.

"Obviously, driveability is still the biggest concern of the team."

Horner also paid tribute to the performances of the two Toro Rosso drivers, who were both making their grand prix debuts.

Sainz scored points for ninth, while Max Verstappen was in the hunt for points when he retired with an engine problem after his pitstop.

"I thought they both drove really well," said Horner. "Both looked like veterans."