Mercedes boss Toto Wolff says there is still "good" steps to come from its Formula 1 car and engine package, even though it has so far dominated the 2019 season.
The F1 team has started the season by breaking records, securing its five one-two finish in last weekend's Spanish Grand Prix.
When Mercedes boss Toto Wolff was asked by Autosport how much more could come from the engine and the car, he said: "There are steps on the power to come but, with mature regulations, it's not those immense steps that we have seen in the past.
"But still some really good work that is being done for engine number two.
"In terms of unleashing more performance of the chassis, I think we still have good ideas.
"It's still just the fifth race with these new regulations and more potential to unlock.
"This is also why we decided to go that way. We felt that with the front wing concept we have followed there is more potential long term, maybe with the risk of a short-term struggle."
Ferrari had the clear edge in pre-season testing but has recently raised questions over its 2019 car concept, although it believes a "quick" fix is possible once the car problems have been diagnosed.
The Italian squad's low-drag front wing solution started promisingly, but there is a suggestion that it has a limited scope to work in to find downforce improvements.
If Ferrari needed to switch to a Mercedes-like concept, it would likely take months of work that could prevent any chance of a fightback in the title race.
Wolff still believes that Ferrari and Red Bull can threaten his team.
"Both teams have the right resources and have tools that could easily make them rebound," said Wolff.
"We've seen a weekend in Barcelona now that was probably one of the strongest that we've had in seven years.
"But we are swinging a little bit with the news.
"If we have a strong weekend from Ferrari in Monaco everybody will say 'this stopped Mercedes, at least it's the end of the Mercedes dominance of this year'."