Renault has delayed a major engine upgrade in order to ensure it delivers the reliability and performance required, according to Renault managing director Cyril Abiteboul.
Renault had been due to deliver its works team and its customers Red Bull and Toro Rosso an upgraded power unit for the Canadian Grand Prix in June, with Red Bull hoping it, combined with its upgraded Spanish GP aero package, would put it in the fight for race wins alongside Mercedes and Ferrari.
However its hopes have taken a hit as Renault will now not deliver the upgrade until Austria or Great Britain at the earliest and possiblity later, with Abiteboul wanting to align it with the third engine change of the season, which isn't due until Hungary.
"We want to do that [deliver the new engine] before the summer break," the Frenchman told Autosport. "We want to keep it in sync with the power unit integration, and we want to do that with power unit number three if possible."
Abiteboul explained that the delay is down to ensuring the engine delivers what Renault expects, without pushing reliability.
"It is something that is still work in progress," he commented. "We are touching some limitations, but we believe the concept that we have introduced this year is the right concept.
"There is innovation in the pipeline and there is performance in the pipeline. The thing we need to get under control is engine reliability, I've said that on many occasions.
"We know there is some fragility in the system that we need to cope with. It is true on the track and it is true on the dyno."
