This was mainly due to the Renault engine lacking performance and reliability, compared to the Mercedes and Ferrari power units.

Red Bull had a terrible start to the 2015 Formula One season with a lack of performance from its Renault power unit compounded by reliability problems.

[6] After the first four races, Red Bull still continued to struggle for reliability and performance, only scoring 23 points, the team's worst start since the 2008 Formula One season.

Renault countered with their own threat to pull out of Formula One as an engine supplier if its reputation continued to be damaged or was otherwise not profitable to the company.

Red Bull had targeted the Spanish Grand Prix where it would make a step forward on performance due to multiple aerodynamic upgrades, but in the end no results had come thus far as both drivers still finished a lap down on Mercedes and Ferrari.