Canadian GP: McLaren-Honda F1 team must 'improve everywhere'

Fernando Alonso and Jenson Button are now on their fourth and final engine after both cars required a change ahead of qualifying in Montreal.

Button's problems were so severe the 2009 world champion failed to take part in qualifying, while Alonso at least managed 14th and moves up a place for the start due to Toro Rosso's Max Verstappen taking a penalty.

The failures came a day after Honda chief Yasuhisa Arai told AUTOSPORT the use of tokens had improved the power unit and provided optimism going into the weekend.

Asked about the areas required for development, a succinct Boullier initially said: "Everywhere."

He then added: "If you want to win you have to be the best in terms of aerodynamics, vehicle dynamics, chassis, driveability, so we have to improve everywhere.

"We are lacking downforce to be at the front, [to have] let's say a top chassis, so we have to work on this to make the car better."

With McLaren hosting its shareholders from Bahrain and in Mansour Ojjeh this weekend, pressure from above would be understandable.

Yet Boullier added: "There is pressure, but that's normal.

"We are all competitors and we want to win and be competitive, so there is pressure on Honda, pressure on McLaren.

"With the shareholders, like any company in the world, they visit us, they provide us with good support, but also they understand.

"We have a duty to report, which is also normal, so we don't have this external pressure.

"We are professional and transparent enough, so they know what we are doing, and I hope we know what we're doing as well."

Arai, meanwhile, described the events of the day as "not satisfying and very sad".

With Alonso's car a fault was discovered inside the engine, necessitating a change, while with Button ERS problems were found, leading to damage inside the system and another replacement.