Renault Sport F1 boss Cyril Abiteboul admits he's been "impressed" by the power unit gains made by the French manufacturer's rivals in recent weeks, and in particular Ferrari.
Although Renault produced what it thought was a significant upgrade for the Canadian GP it doesn't appear to have closed the gap.
At Silverstone it was clearly lagging behind, with the Red Bulls unable to keep pace with the opposition, and the works cars out of the top 10 in qualifying.
"I'm just impressed by our competitors," Abiteboul told Motorsport.com.
"I'm impressed by what we are doing, but I'm also impressed by what they are doing, because it's a fact that the gap is not really reducing. What we are doing is just allowing us to keep that gap.
"I do think Ferrari in particular has made an important step for the past few races, with its works team and also its customer teams. It's very visible, and we have to factor that into what we are doing, and to the priorities that we put.
"We have to keep on delivering what we're supposed to deliver on power."
Abiteboul said the gap to the opposition was exacerbated at Silverstone by the increased time spent at full throttle, a result of rising downforce levels and gripper tyres compared to previous years.
Red Bull's Max Verstappen said that the French engine was missing "70-80bhp," and that it was becoming "a struggle" at a circuit that has more flat out corners now.
"It's really amazing how much the tracks are changing," said Abiteboul. "Particularly this year with the extra effect of normal aero development and tyres with more grip, but also lots of tracks have been resurfaced.
"We don't always know what to expect from this resurfacing, and it really was a surprise to see the amount of grip offered by this new Silverstone, and the percentage of the track where you are now on full throttle.
"It makes it one of the most power sensitive tracks that we've seen so far. A couple of years ago in everyone's mind a track like Montreal was one of the most sensitive. It's actually a joke now, compared to Austria or Silverstone.
"So I think that some of the comments made by the drivers need to be put in the context of the evolution of the track. You don't necessarily expect that from Silverstone, but in reality this is the new Silverstone."