Red Bull team principal Christian Horner says the promising aspects of Renault's engine development are still several months away from making it to the car.
Renault has struggled for performance since the introduction of the current engine regulationsin 2014 and has seen the gap to front-runners Mercedes increase this year. For Red Bull, the lack of power and reliability has resulted in its worst start to the season since 2008, but Horner says improvements will take time and development this year is focused on preparation for 2016.
"They are working hard behind the scenes and coming out with some interesting concepts," Horner said of Renault. "The problem in the engine world is everything has a long lead time, you test as a single cylinder first before you go into a V6 format. They are obviously still working on that single cylinder format which means the lead time to any V6 is several months away. We're hopeful of seeing something before the end of the year.
"I think there's aspects that have been encouraging, but then how does that translate to full scale? It's like going from the wind tunnel onto the circuit at that stage. But yes, there have been some encouraging results on the test bed."
Asked if the developments would make it to the track this year, Horner added: "We certainly feel it would be an advantage to get it on the car this year because at least we're learning about the characteristics etc. In reality this year is compromised anyway for us so it's important to use the time constructively to put together a better package for next year."
Horner said the reliability issues are mainly down to the internal combustion engine (ICE), but stressed that Renault has to focus on all areas of the power unit to improve.
"I think with all these things there's never a silver bullet and I think yes the combustion unit is a predominant factor but I don't believe it is everything. Again, it's the integration with the other elements which is quite critical. For sure a larger element is within the ICE."