McLaren says upgraded Honda F1 engine better than expected

Honda used its final four power-unit development tokens ahead of the Russian Grand Prix, and then ran the system in Fernando Alonso's McLaren only for the opening practice session at the Sochi Autodrom.

Alonso completed 16 laps before reverting back to a previously used power unit, albeit boasting a new turbocharger and MGU-H, for the rest of the weekend at Sochi.

After assessing the data so far, racing director Eric Boullier said: "It was very positive.

"It actually beat all the expectations on the data, the dyno measures.

"It worked as per plan, and has improved.

"So we introduced this engine here because we know it's a track layout that doesn't suit our package, and then run it from the race in the USA."

From the forthcoming race at Austin onwards, McLaren and Honda will run the new unit with Alonso, with the plan to hand team-mate Jenson Button the updates for Mexico.

Honda motorsport boss Yasuhisa Arai also declared himself satisfied with the new package, although it continues to possess an Achilles heel that will be a focus over the winter.

Arai said: "At this circuit, on the engine itself, there has been a scheduled improvement, but total horsepower, with deployment, is still weak."