Honda's engine performance is very close to that of Renault's, according to its motorsport boss Yusuke Hasegawa.
In Baku, Honda claimed its ‘spec 3' engine was worth several tenths of a second, and Hasegawa says that the introduction of ‘spec 3.5' in Spa has closed the deficit to Renault.
“From the beginning of the season, we have been improving the power unit – not only in terms of performance but also reliability,” Hasegawa was reported as telling Autosport.
“Since we introduced spec 3.5 engine, I think that level of performance is very close to the Renault.
“I cannot say it's better than Renault but the important thing is the reliability is much better.”
Hasegawa also said that the Japanese manufacturer is as close as it has been to its engine rivals since its current stint in the championship began.
“We're not close enough, but the gap is very small compared to last year and the first year,” he claimed.
Honda plans to keep its current concept for next year and evolve it rather than make dramatic changes as it did last year.
Hasegawa is hopeful Honda can match its rivals next year.
“There is no doubt in this current concept,” he said.
“There is no reason we can't achieve the same level of performance with the current concept.”
The manufacturer discovered a hydraulic leak on Alonso's engine after Friday practice and elected to swap the power unit in its entirety rather than attempt a fix.
Though Hasegawa was frustrated, he feels the fact the problem was not a key issue was positive.
“We had an issue on Friday, but it was not a fundamental ICE issue,” he said.
“The team could concentrate on the settings for the weekend, which is very positive.”
Formula 1 continues with this weekend's United States Grand Prix on October 20-22.