Honda are planning to introduce two final upgrades to its power unit during the 2016 season, before switching focus to next year.
The Japanese manufacturer is looking to get on terms with rivals Renault, Ferrari and Mercedes after it entered into the current engine era a year late, which has forced it to play catch up – whilst a design error in its debut season further hampered progress.
Honda have taken steps forward in '16, particularly with its ICE intake update at the British Grand Prix, allowing partner team McLaren to regularly challenge for points, but they still remain some way off the lead pace and Honda are hopeful that gap can be closed further before the end of the season.
Honda engine chief Yusuke Hasegawa told Autosport that there are plans to introduce two more upgrades this year as it looks to spend its remaining ten tokens, with the first likely to arrive at this weekend's Belgian GP.
"Sakura is always developing, so as soon as we are ready, we will introduce it," said Hasegawa.
"We only have nine races, so even if you have an idea, we only have two chances to introduce it," he explained, "so we have one chance at Spa and one more after that and the plan is still to use all of the tokens."
Honda will then turn its attention to next year when the current token system is scrapped, allowing for more freedom to introduce larger upgrades, but Hasegawa isn't 100 per cent certain of when exactly that focus switch will happen.
"This is the biggest job for me, deciding when to divert resource from this year to next year," he added. "So far, I won't give up on this year, but maybe this month, I have to decide."