Red Bull was constantly critical of former power unit suppliers Renault in the past for their problems with outright power compared to rival suppliers Ferrari and Mercedes since the start of the V6 turbo hybrid era in 2014.
"Last year we were definitely down on power, and on those critical tracks it was definitely quite painful," Verstappen told Autosport. "This year we are close to Mercedes. Ferrari is of course flying on the straight, but they have less downforce.
"We look alright against them [Ferrari], but sometimes they have that upper hand like at Silverstone, they had that slight advantage."
Since their switch to Honda power at the start of the season, Verstappen has taken two wins at Austria and Germany, and came within two-tenths of Valtteri Bottas' pole position time at Silverstone, a track noted for its dependency on engine power.
Verstappen was a bit worried prior to the race at Silverstone, but believed afterwards it showed how far the team had progressed, with its best showing at the circuit under the current power unit regulations so far.
While the next two races at Spa-Francorchamps and Monza are rumoured to favour Ferrari's power advantage, Red Bull team principal Christian Horner is also happy with the progression and is confident of more positive moments to come.
"Austria is power-sensitive, Silverstone is power-sensitive and we've been competitive at both of those venues," he said. "Hockenheim, we were very competitive in qualifying and then the quickest car in the race. Across a variant of circuits we've managed to make a good step forward."
Bahrain International Circuit - Winter testing