Honda was left both encouraged by the performance of its power unit upgrade at the Canadian Grand Prix but disappointed by a reliability issue, according to its F1 technical director Toyoharu Tanabe.

Like Renault and Ferrari, Honda introduced its first power unit update of the season in Montreal to coincide with the power-sensitive circuit. After promising signs during practice, Pierre Gasly suffered a loss of power at the end of FP3 and was forced to revert to an old specification for qualifying before taking a second new specification — and with it a grid drop — in the race.

“So we brought an updated power unit and we had both good and bad moments this weekend,” Tanabe told RACER. “Generally the new spec worked as we desired, but on the other hand we had a failure on the new spec. We will analyze the cause of the failure in Japan, so we don’t know very much detail about it yet.

“That is the disappointing point of view, because we always tell people that we want to be both reliable and improve performance. Reliability is important, but we had a kind of unknown failure in Canada so we need to find out the reason and then update.

“The other thing is a good thing: We could see some performance gains with the new, updated power unit, so that’s good.”

Gasly took a new power unit on Sunday morning as it only cost him three places on the grid, and Tanabe admits that the original update that suffered a power loss could prove unusable in future.

“I cannot say with any certainty if it is too damaged or if it’s OK; we will find out. But it’s not light damage.”

With Brendon Hartley getting close to reaching Q3, an encouraging Saturday was soon followed by a first-lap clash with Lance Stroll that eliminated the New Zealander in the race, but Tanabe is hopeful there will be little in the way of repercussions from that incident.

“He started from 12th place, which I think was a good position to have a race in the midfield. Unfortunately he crashed, which is disappointing, but he’s OK, that’s the good news. So we missed one race sample of data from the new specification of power unit and that’s a little bit disappointing, but it’s a racing situation and Brendon is OK, so that’s good news.

“Visually the power unit looks like no problem, but it was a high-G impact so we will investigate and will check everything.”

-Chris Medland