Honda has "nearly finished" finalising its 2017 power unit concept after switching complete focus to next season.

The Japanese manufacturer last introduced a power unit upgrade at the Malaysian Grand Prix, with Fernando Alonso receiving the upgrade at Sepang and Jenson Button getting it a week later at Suzuka. With development of the 2016 power unit complete, Honda has switched focus to next season and head of F1 project Yusuke Hasegawa says it is close to finalising its design.

"The concept is nearly finished," Hasegawa told F1i. "We have started engine testing on the dyno for 2017, so we will continue to improve performance through testing until very close to next season. We cannot go into any details at this point."

While the token system will be lifted - allowing a potential overhaul of the power unit concept - Hasegawa says much of this year's development will prove beneficial to next season's performance.

"Some of the development that we have put into effect in 2016, like weight reduction and reliability updates will always be useful in any situation. Though we cannot go into technology specifics for 2017, the overall power unit regulations will not change drastically, so many things we learned from 2016 can be used as fundamental technology and data for 2017."

And Hasegawa says the final two races will also allow Honda to improve on its knowledge ahead of next season, although no work is planned with 2017 in mind.

"We do not expect to bring in anything new specifically to target 2017. However the mappings and settings we perform for each circuit always proves worthwhile gathering data for next year."

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