McLaren's Eric Boullier says that the necessity to save fuel cost Fernando Alonso up to 50 seconds in last Sunday's Russian GP.
While the Frenchman was happy with both his drivers' reliable run in Sochi, and Alonso's sixth place finish and subsequent points, fuel saving constraints remain an issue at McLaren-Honda.
"We're relieved and happy for the guys back at the factory because everyone is pushing very very hard," Boullier said.
"In terms of the race, we had to save a lot of fuel but Fernando had a couple of laps at the end when he stopped saving fuel. You could see the pace difference was then massive.
"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]."
While progress is still ongoing, Boullier admitted however that the team's performance in qualifying still requires more effort, as does the development process of deployment.
"We keep bringing performance and missing Q3 for one tenth was a bit of blow. This track did not suit us in terms of lay-out and especially fuel saving. But I think on other tracks we will be able to use more pace out of the car.
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