Renault wants 2017 F1 MGU-K back for Russian Grand Prix

Reliability concerns about the new MGU-K, magnified during F1 pre-season testing, prompted the French manufacturer to adopt a no-risk strategy at the first races for its works team and customers Red Bull and Toro Rosso.

The move back to the 2016 version has not come without penalty, though, as the older specification is 5kg heavier and requires an extra 1kg air bottle for cooling.

With F1's latest generation of cars already on the weight limit, the extra bulk is not ideal, which is why Renault has vowed to do all it can to bring the 2017 version back as soon as it can.

Although it has not specified when that will be, sources have indicated that a return for the Russian GP at the end of April - the fourth race of the season - is most likely.

"We are planning to bring back the 2017 one as early as possible," Renault F1 managing director Cyril Abiteboul told Autosport.

"As you know, the [power of the] MGU-K is governed by regulation - 120KW - so it is not like we can change that.

"But there is weight, there is a little bit of cooling and a little bit of the condition that we can use it.

"All of that was slightly improved with the 2017 one, but it is not a game changer."

When asked if it was possible that the MGU-K would be fitted before the second batch of engines come into play, he said: "Absolutely.

"You know we have the mix and match possibility in the engine, so we are not locked into what we have.

"We will be bringing it as early as we can."