Mercedes claims it may be just a single upgrade package away from victory in 2023.
Former Formula 1 driver Ralf Schumacher said after the Canadian GP that he thinks Aston Martin is currently "a tad ahead of Mercedes with these improvements".
Indeed, Aston Martin unveiled a major upgrade recently, prompting Schumacher to predict that Fernando Alonso "will be Max Verstappen's toughest competitor at the Red Bull Ring" next weekend.
Mercedes, though, insists it is also closing in on Red Bull's dominance, with boss Toto Wolff claiming Montreal was a tough test for the 'B' car package.
"I am no longer afraid of the next circuits that are coming up," he told Auto Motor und Sport.
And an unnamed Mercedes engineer also told the German magazine: "We're only one upgrade away from victory."
Wolff announced that those upgrades are now in the pipeline.
"A big one in Silverstone," he said, "and a smaller one after that.
"We've learned a lot since we changed the concept of the car," the Austrian added. "The correlation between simulation and the race track has improved a lot so we're now implementing step by step."
However, some are wondering how Mercedes and others are managing to so significantly upgrade their cars mid-season within the confines of the budget cap.
La Gazzetta dello Sport claims the FIA is currently taking a close look at whether the top teams' non-F1 activities - including the design of boats, bikes and road cars - have created loopholes in the strict budget cap rules.
"There was a request for clarification for Mercedes, Ferrari, Red Bull and Aston Martin," reported correspondent Louis Perna.
Wolff says he isn't worried about Mercedes breaching the cap - as Red Bull was found to have done in 2021.
"We have 46 people controlling all of our expenses, down to the last screw," insisted Wolff.