Honda says it is seeing progress on new Formula 1 engine specifications tested on its dyno but does not understand why it is unable to transfer that to the track.
The Japanese manufacturer has been working on significant tweaks to its V6 engine in a bid to improve reliability and performance and close the gap to rivals.
It had hoped to introduce its first major performance upgrade of the season in Canada, but decided to wait to allow for further testing and development.
“We can’t create good conditions on the dyno,” Hasegawa told Motorsport.com. “We need to create the same conditions from the track on the dyno.
“The operational conditions are different so we need to understand why that makes a difference to the reliability.
“Last year, we could prove engine reliability on the dyno so we need to understand why now there is some difference from dyno to the circuit running - it’s not easy.
“We need to improve the accuracy.”
McLaren racing director Eric Boullier declared Honda’s performance “not good enough” after a late engine failure for Fernando Alonso denied the team its first F1 point of 2017 in Canada.
It came after the outfit suffered yet another MGU-H failure in FP2 with Stoffel Vandoorne forced to revert to one in his pool.
“We have the countermeasure part but we didn’t introduce it in Canada because we would get a penalty,” said Hasegawa.
“If we’re confident with the countermeasure, strategically we may choose some circuits to introduce it. We don’t want to have a failure on the circuit and take a penalty.”
The two failures heaped more pressure on Honda, which faced criticism at the start of the race weekend when McLaren’s executive director Zak Brown expressed “serious concerns” about Honda’s F1 capability.
Five things we learned from the Canadian GP
Haas unhappy with Sainz's "dull" crash excuse