The head of Honda's F1 project, Yusuke Hasegawa, says the Japanese manufacturers intends to use its (14) remaining engine development tokens for a limited number of major upgrades as opposes to a series of smaller, less significant changes.

Yet to spend any of its tokens since the season got underway, Honda, with a keen eye on its rivals, is awaiting the right opportunity for the first significant upgrade.

"Of course we keep developing," Hasegawa told Autosport, "we just have to decide when we can expect to introduce the new technology or tokens.

"We have some tokens," he continued, "but it's still limited and we don't want to use them for tiny steps, from a tactical point of view. We'd like to use tokens effectively rather than gradually.

"We need to see the exact result of the development. I hope it is a big step forward. I heard some of the items are very promising but before we get it I don't know the exact benefit. The ICE and ERS are being focused on."

Renault, which is on the verge of a major upgrade, has 24 tokens remaining, having used one in Bahrain, whilst Mercedes and Ferrari, which spent two and three respectively for Russia, have 11 and 6 remaining.

The controversial token system is scrapped after this season, and Hasegawa admits it won't be a moment too soon.

"I'm happy that F1 is removing tokens for 2017 but it will be a major challenge for the engineers," he admitted. "We can have more freedom for development, which is good. Cost reduction is very tough for every engine manufacturer so we're happy."