Honda says its recent improvement in power unit performance has come through learning how to exploit the potential of its 2021 concept.

Red Bull’s straight-line speed gains at the French Grand Prix (pictured) — where a second Honda power unit was introduced — led to Lewis Hamilton questioning where the step forward had come from, as upgrades are only allowed for reliability reasons this year. With the Japanese manufacturer introducing a brand-new concept this year, Honda’s F1 technical director Toyoharu Tanabe says any step forward has come from experience of how to use it best.

Asked whether Honda is getting closer to its maximum potential, he replied, “Yes, because we started using this 2021 new power unit from the pre-season test and then we have been gradually learning how to use it. We improved our weaknesses, and then we pushed our strengths. And as a result the base specification of the performance is the same but the trackside performance, I believe we have been improving.”

Asked about rumors that Honda’s second power unit could have provided a performance gain as big as 15 horsepower, Tanabe replied: “I’m very happy if it is true!

“It’s not true. Under the current regulations, any performance update is not allowed during the season. As a result, our second power unit is the same as the first in terms of specification and performance.”

Tanabe says any claims that Honda has made a step forward through changes to the power unit itself are overlooking the fact all manufacturers have to approve developments.

“The current performance improvement is as a result of the hard work from Honda, and the teams. Under the current PU regulations, we need to submit any changes — we’re only allowed to change for reliability, cost reasons, and logistics. Then we need to submit very detailed changes to the FIA first, and the FIA approved those changes.

“The FIA distributes all the documents to the other PU manufacturers. So, we need to have approval from the other PU manufacturers to change any single part’s specification. Why we are doing such detailed investigation (into changes) is that a long time ago some teams improved their performance by making a change to improve their reliability.

“So, we are very careful to change the performance. It is not possible to improve the performance during the season. That’s my answer to that suspicion.”