Max Verstappen says Red Bull's chassis performance is now 'really good' and the team would be dominating F1 if it had Mercedes engines.
The Renault-powered team have been on the back-foot compared to Mercedes in particular since the start of the current hybrid V6 regulations in '14.
And Verstappen told Autosport: 'I think that if we had a Mercedes engine in the back, they would never see us again.'
Though Renault has made gains in recent years, the Belgian said he still had 'less horsepower than the other manufacturers, apart from Honda' in 2017 - highlighting the MGU-H as a particular weakness.
'Ours just isn't that stable compared to what Mercedes and Ferrari have,' Verstappen added.
'But it has to do with several things. Otherwise they would have solved it a long time ago, of course.'
The 20-year-old believes his team got it wrong when they went for a low drag configuration at the start of 2017 when the rule changes put more emphasis on aerodynamics.
'They thought about going for a low drag configuration, but for some reason it just didn't work out,' said Verstappen of Red Bull's poor start to last year.
'Maybe it was a bit too optimistic.
'But you've seen that the team can turn things around very quickly.
'Of course, by then your season is already lost, but it does give you confidence for the future that it can go in the right direction.'
tagged in Ferrari