Honda has set the minimum target of overtaking rival engine maker Renault in 2018.
After three abysmal years with the Japanese supplier, McLaren have dumped Honda and will next year swap engine deals with the currently Renault-powered Toro Rosso.
Since 2015, Honda's has been clearly the slowest engine on the grid, but boss Yusuke Hasegawa insisted: "I think we're reducing the gap, even if we are not close enough yet.
"Obviously we hope to do more over the winter," he is quoted as saying by El Mundo Deportivo.
"We must definitely reach Renault and overtake them [in 2018].
"Our goal for 2018 is to go beyond overtaking Renault, even if we do not want to reveal our plans right now."
The 2017 season ends this weekend with the Abu Dhabi Grand Prix.
