But the report claims Mercedes engine chief Andy Cowell is "confident Mercedes will succeed" in breaking through the 1000hp barrier before the regulations conclude in late 2020.
"If the world champions maintain their approximate development speed, 1000hp will be reached in 2019," correspondent Michael Schmidt said.
Ferrari is next in the power rankings with 934hp, followed by 907 for Renault and Honda's 860hp.
Finland's Ilta Sanomat reports that Ferrari is pushing to get an extra 40hp from its engine in 2018, even though engine boss Lorenzo Sassi is moving to Mercedes.
"I don't know who said Sassi is a phenomenon, but I don't remember saying it," Ferrari president Sergio Marchionne told Marca.
"What is true is that our problems were due not only due to him. Our intention was to keep him in GTs, but unfortunately he decided to leave and continue his career elsewhere.
"For the team it's a normal change and now we have Corrado Iotti and we're fine with him," Marchionne added.
Finally, Renault's Cyril Abiteboul told Auto Hebdo that he blames former boss Flavio Briatore for the French marque's current power deficit.
"We are still paying the price for Flavio's decision in 2007 to dismiss hundreds of people when engine development was frozen," he said.