Yasuhisa Arai says Honda remains optimistic that it can get to the bottom of persistent reliability issues to ensure McLaren is on terms with leading rivals by the end of the 2015 F1 season.

The Japanese firm is coming under increasing pressure to bring its new power unit up to a more competitive level following a series of technically-motivated retirements in recent races, including three in a row for Fernando Alonso.

Despite this, Honda says it is working closely with McLaren beyond the power unit in an effort to better integrate it into the MP4-30, a method he hopes will see the car take a turn for the better before the year is out.

Related Articles

"We are working very hard not only on the engine but on the aerodynamics and chassis side. The technology is working step-by-step and we are making very good progress from Australia to Canada. Maybe in a few more races in the second half of the season we can achieve top rivalry and good competition with top level teams."

Though the disappointing results have brought McLaren-Honda under close scrutiny, Eric Boullier insists there is more pressure than normal from the team owners.

"There is pressure," he insisted. "That is normal. We are all competitors and we all want to win. We want to become competitive, so there is pressure on Honda, pressure on McLaren and the shareholders just like any company in the world.

"They are here to give us support and we have to report to them which is usual but we don't have any extra pressure. We are professional and transparent enough with what we are doing."