Renault give Red Bull deadline

Renault have given Red Bull a May deadline to decide whether they want to continue using their engines in 2019.

The long-running partnership's future beyond the end of this year has been in doubt for some time with an expectation that it will end after Toro Rosso, Red Bull's junior team, took a works supply of Honda engines.

But Red Bull chief Christian Horner said on the opening day of testing that the tie-up could still "absolutely" continue into 2019.

"All things are open for 2019 onwards," said Horner. "We will obviously pay close attention to how things develop at Toro Rosso but there are no preconceptions as we head into the season."

Renault boss Cyril Abiteboul also left the door open to a renewal but warned: "we're not going to hang around forever".

"I know what Christian is referring to when he says he has options," Abiteboul told reporters. "He is absolutely right. But one thing that is clear is planning.

"At the end of May there needs to be some clarity as to who is supplying which team. As far as we are concerned, that will be our deadline."

Under F1's Sporting Regulations, engine manufacturers must inform the FIA by May 15 which teams they have an agreement with in place to supply for the following season.

Renault respond to Red Bull 'concern'
With F1 reducing its penalty-free engine limit to three units for 2018, Renault have prioritised reliability in a bid to avoid engine penalties for their works team and two customers.

But Red Bull have been counting on a big performance jump from the French manufacturer in order for them to challenge Mercedes and Ferrari for Formula 1's world titles in 2018.

Asked about Renault's strategy, Horner said: "It's a concern. If the headline figures Mercedes are quoted are real [being on the brink of 1,000 horsepower] the gap will only broaden.

"Obviously Renault have their own team now and their own demands to meet and they've had a positive year off track from a reliability perspective. But we're hopeful of seeing more performance and performance converging between the engine manufacturers."

But Abiteboul said such comments about his company's engine programme were "no surprise" from their long-standing customers.

"We don't need to speak, we are speaking through you indirectly!" he told Sky Sports News.

"I know Christian and I know Red Bull. I know that when the engine is not reliable it's not reliable and when it's not reliable it's not performing enough.

"There's absolutely no surprise, it's the same business for 12 years with Red Bull Racing. We know what to expect."

The Renault chief believes the reliable start the team's 2018 engine has made to winter testing is a good sign for the season ahead.

"The engine has done the step that we were expected in terms of reliability with 250 laps covered by all three teams [on Day One], which is a lot," added Abiteboul.

"I think it's the best start we've had since the introduction of the V6 in 2014. But we are very careful, it's early days."

Sky Sports F1 is the only place to watch every Formula 1 Grand Prix, qualifying and practice session live in 2018. Get Sky Sports F1.