Renault Sport concedes it took a 'step backwards' between pre-season testing and the Australian Grand Prix after a dismal first weekend that saw it called out by Red Bull team principal Christian Horner for its poor performance.

Under pressure to avoid a repeat of the reliability and performance issues that beset it during the 2014 season when F1 adopted V6 hybrid power units, Renault was confident it had made good progress over the winter.

However, the opening round would see Red Bull in particular struggle for pace, with complaints about driveability coming from Daniel Ricciardo, while Horner blamed 'vibrations' from the engine for causing Daniil Kvyat's gearbox to break ahead of the race.

Related Articles

Furthermore, with both Ricciardo and Toro Rosso's Max Verstappen suffering ICE problems during the weekend - the latter being forced out of the race with his problem [pictured] -, Renault would become the scorn of the top brass at Red Bull as it vocalised its calls to change the engine regulations.

Indeed, Renault says it is aware its efforts have been disappointing, but while it insists it is committed to turning its fortunes around, it says it will not resort to a redesign.

"From the start of the weekend we've faced a number of technical issues, both at Red Bull and Toro Rosso," said director of operations Remi Taffin. "Reliability has been below par, with Daniel Ricciardo and Max Verstappen suffering ICE problems. The two are not related and we are already investigating a recovery programme to make sure we do not see a repeat.

"The biggest issue has been the driveability, which has made it hard for all the drivers to feel comfortable in the cars. It affects pedal application and confidence in the corners so has cost lap time and points this weekend. It's related to the maps, or the way the Power Unit is configured, so while it's definitely not an easy fix, it does not require a complete redesign.

"We have got a lot of work to do before Malaysia but equally a lot of motivation to not repeat the same issues we had this weekend."

Renault's increasingly strained relationship with Red Bull comes as rumours grow that it is considering reviving a sole factory effort or go into partnership with another team - similar to BMW's former tie-up with Sauber -, with Toro Rosso and Force India considered the most likely candidates.

Red Bull and Renault won four consecutive world titles together between 2010 and 2013 with Sebastian Vettel at the wheel, though the French firm - which won two world titles with Fernando Alonso as a fully-fledged manufacturer effort in 2005 and 2006 - feels it did not receive the credit for its contribution that it deserved, which is likely to make the current pointed criticism more sharply felt.