PARIS (AP) Red Bull team principal Christian Horner is worried that his drivers will need up to nine engines this season following a complicated start for both Daniel Ricciardo and Daniil Kvyat.
Ricciardo's engine blew at the end of last Sunday's Bahrain Grand Prix, although the Australian driver was able to make it over the line in sixth place. It was the third engine Ricciardo has used in four races.
Teams are only allocated four engines per driver over a season, although they are pushing for a fifth engine. However, given Red Bull's ongoing problems with engine manufacturer Renault, Horner is not optimistic of a rapid improvement within the current rules.
''The teams agreed unanimously in Malaysia to introduce a fifth engine,'' Horner said Thursday on Formula One's official website. ''For us we would need that number to increase to seven, eight or nine engines for the season. Unfortunately these are the rules and we are not looking great within these rules.''
Red Bull won four straight constructors' and drivers' titles with Sebastian Vettel behind the wheel from 2010-13, but is in fourth place so far and is already lagging 136 points behind Mercedes.
Owner Dietrich Mateschitz threatened to withdraw from F1 unless Renault makes its engines more competitive. Although Horner says the partnership - which runs until the end of next year - will continue, he again urged the French-based supplier to do more.
''In reality our best chance is with Renault and vice versa. We have won 50 Grand Prix (races) and eight world championships together, so sometimes frustration boils over,'' Horner said. ''Dietrich doesn't talk publicly very often, but when he does you have to listen. What he was conveying was: Renault should do the job better or not at all.''
But Horner has ''no idea'' when Red Bull will start competing for podium places again, after Ricciardo impressed in his debut season last year with three GP wins.
''To be realistic our problems are not short term so there will not be any short-term fixes,'' Horner said. ''We have to take a bit of pain at the moment, and if that is the foundation for a better future then you've got to.''
The highly-rated Kvyat came to Red Bull from Toro Rosso with a strong reputation as one of F1's most promising young drivers, but the 20-year-old Russian has not finished higher than ninth, retired from the Chinese GP with engine failure and did not start the season-opener in Australia.
''We are not remotely in the position that we expected to be,'' Horner said. ''Some of our problems are beyond our control ... We haven't given our drivers a fair chance. They've had to fight with so many issues that driving somehow almost became a second thought.''
Further compounding the misery for Renault - which also supplies Toro Rosso's engines - is that Toro Rosso's teenage driver, Max Verstappen, has failed to finish the past two races, also retiring with engine failure in Shanghai and curtailed by an apparent electrical fault in Bahrain. Verstappen's teammate, Carlos Sainz Jr., also retired in Bahrain.
Red Bull and Toro Rosso have two weeks to improve their cars before practice for the Spanish GP begins on May 8.