F1 Strategy Group to vote against proposal for a fifth engine

Regulations came into force at the start of the year stating the teams would be restricted to the use of four 1.6-litre V6 turbo-charged power units for 2015 after being allowed to use five last term following the implementation of the new regulations.

A return to five has been on the agenda for several weeks, with a preliminary agreement put in place in Malaysia at the end of March.

But following a period of debate - led by Red Bull given the catalogue of issues it has sustained with its Renault powerplants this season - the Strategy Group will vote 'no' at their meeting at Biggin Hill on Thursday.

AUTOSPORT understands Mercedes and Red Bull are in favour, but on cost grounds Williams, Force India, McLaren and Ferrari will vote against.

For Red Bull, such a decision will only add to the team's problems as it has already used six power units this season - four for Daniel Ricciardo and two for Daniil Kvyat.

Already expressing his frustration at the likely outcome, Red Bull team principal Christian Horner told AUTOSPORT: "It's an important Strategy Group meeting in a week's time, and I'm sure it's certain to be on the agenda to be discussed there.

"But as is the modern world of F1 people agree things in meetings and then change their minds."

Underlining Red Bull and Renault's woes this season, Horner accepts that one extra unit wouldn't have a huge effect in the long run.

"Whether it's five or eight engines, it doesn't make a difference for us," he added.

"It's inevitable we are going to have to take eight, up to nine engines this season."

RELIABILITY THE FOCUS

Horner is hopeful Renault has finally got its act together on the reliability front, starting from this weekend's Spanish Grand Prix.

"They have been working very hard over the past few weeks, all of their efforts have been focused on reliability," added Horner.

"I don't think we will see performance improvement, but hopefully we will see reliability improvement.

"As you can imagine, having used six engines of the permitted eight in the two cars, their focus is very much on reliability at this moment in time.

"Naturally both sides are frustrated because neither party wants to be in the situation we're in.

"We are doing the best we can to support each other and get performance and reliability to the car as quickly as we can.

"Most definitely it's been a horrible start to the year for Renault, and as a result of that a disappointing start for Red Bull Racing.

"But everybody is focused on the goals and targets of what lies ahead."