Fernando Alonso finished sixth, one lap down, but was 52.829 seconds behind fourth-placed Valtteri Bottas at Sochi.

Boullier says that gap was entirely down to the Honda engine's fuel appetite compared to rival power units.

"We can see that we are the team that have a lot of fuel saving for obvious reasons," said Boullier.

"But with Fernando you could see towards the end of the race he was more than 1.2s faster [per lap].

"So without fuel saving we'd save another 50s which we would've had at the end of the race.

"If you look, we are with Williams [without fuel-saving] so it's the kind of progress we need to go [further].

"But that the pace was good and the drivers were happy with the car balance.

"Fernando had some fun."

McLaren boss Ron Dennis knows only too well where his current problems lie - and makes no secret of the fact that if the team can get on top of this tyre heat issue then they may unlock the key to being able to take the fight to Renault.

"We go racing to win and the very reason we are strong in the second part of the race, is exactly the same reason why we are struggling a bit in qualifying," said Dennis.

"We just don't aggressively push into the tyres and that means that in qualifying we don't get enough energy into the tyres and that makes us struggle a bit. But these things are understood and we'll change the car. We've got a very extensive program, which I hope we can now accelerate into Imola, which is our target."

Although Dennis will not talk specifically about what the team are changing on the car, he has confirmed that he is not concerned about the aerodynamic potential of the MP4-20.

"I think the aerodynamics in the car are exceptional but there's several things in the car that are very good. And if Pedro can set the fastest lap you see the strength of the car at the end of the race and there's quite a few things that work.