Honda's Yusuke Hasegawa, who heads the manufacturer's efforts in F1, believes the efficiency of its power unit's Energy Recovery System is now on the same level as Mercedes' ERS.
The unit's energy recovery capabilities were Honda's Achilles heel last season when McLaren endured a dismal 2015 which saw it linger at the tail end of the grid all year round.
Honda therefore focused most of its development work last winter on improving its power unit's ERS, with Hasegawa now claiming that progress has brought it up to the level of Mercedes' engine, as McLaren-Honda's recent performance uplift in qualifying has demonstrated.
"From an energy recovery system point of view, we have already achieved our target, which is already on Mercedes level," the Honda F1 chief said.
"Our recovery system's performance is not very different to the top teams, I am very confident about that.
Honda's will now likely zoom in on an internal combustion update, for which it has yet to spend part of its remaining 12 development tokens.
"There is always some room to improve, but definitely we need to concentrate more on the internal combustion engine performance," Hasegawa concluded.