Red Bull Formula 1 drivers Max Verstappen and Daniel Ricciardo aren't convinced by the FIA's claim that the Renault power unit they race with is within 0.3 seconds of rivals Mercedes and Ferrari.

The FIA introduced tweaks to the power unit regulations for 2017 to try and create convergence, including a removal of the token system in a bid to allow the likes of Renault and the still-ailing Honda to catch up.

F1 race director Charlie Whiting claimed ahead of the Russian Grand Prix weekend that the FIA's plan for engine convergence had been achieved, with its calculations showing that the top three power units were separated by no more than 0.3 seconds.

The claim has split opinion in the paddock, with both Verstappen and Ricciardo believing that it has been too optimistic about Renault's true standing as Red Bull continues to struggle for power compared to its rivals.

"In the last few years we have kind of felt like the chassis has been a lot closer to where it needs to be, and it is more power unit we are looking for," Ricciardo explained. "I feel this year so far we are definitely trying to find a jump in both ends. The power unit is not something new to us now, like he have experienced this deficit the last few years.

"So looking at the gap you'd think it is more than 0.3 seconds. I'd definitely put money on that. But I certainly feel that there is a bit of that in the chassis. I said it already, I feel now it is 50/50, the improvement we need to make on both ends.

"If we got within 0.3 seconds that would be nice. But it would still be 0.3 seconds and we want to be even closer, but I feel we are further off that."

Verstappen went as far as questioning the validity of the tests carried out by the FIA to measure engine convergence at the Circuit de Barcelona-Catalunya in Spain.

"I have heard how they did the calculation and if you cancel out all the fast laps with the good power, the full power modes, you can't calculate like that," Verstappen said.

"You have to take into consideration the fast laps. At the end of the day as a team we know where we have to improve, that is chassis and engine, so it is definitely more."

Latest Tweets from Crash.net & GPF1rst