Horner defends Red Bull's fuel choice

Red Bull is currently the only one of F1 six customer teams not to use the same brand as the associated manufacturer team, although McLaren is planning to go with Petrobras in 2019.

Wolff suggested that it would have been better for Red Bull to stick with the brands around which the Renault engine was developed, citing the fact that Mercedes customers Williams and Force India benefit from using Petronas, as used by the works team.

In addition, anyone choosing their own fuel/oil has to pay the engine manufacturer for the dyno time required to prove their products.

However, Horner insists that Red Bull benefits by going its own way on fuel.

"We see it as an advantage," Horner told Sky Sports News. "We have a great relationship with Exxon, and have done for the last 12 months.

"They're producing some great products. Their products won three grands prix last year.

"Obviously there are additional burdens involved in that, because they're a different supplier than what the works team has, it just means they've got to run more engines on the dynos, which obviously we have to cover the cost for.

"But we wouldn't be using it if we didn't see it as a technical advantage. They are a great company, great to respond, very, very quick, and from our perspective, we see it as an advantage."

Too early to judge form

Horner says it is too early to judge the form of the top teams heading into the first race, although he believes that Mercedes still has an edge on its main rivals.

"I think it's so hard to draw conclusions. You get a bit of a flavour. You see Mercedes are in great shape, you see Ferrari are looking strong. We hope we're there or thereabouts.

"I think it will be great for F1 if there are a few teams in contention this year. But Mercedes rest assured are definitely going into this championship as very much as the favourites."

He also played down talk of a deadline for Daniel Ricciardo to make a decision on his plans for 2019 and beyond, despite Helmut Marko suggesting that one had been agreed.

"Daniel obviously needs to make sure that he's comfortable and he's making the right decision for next year. From our perspective we've obviously got plenty of options.

"Our desire is to continue with Daniel, and at the right point in time there'll be an opportune moment to sit down and discuss the future. But it feels a bit early at this point in time."