Red Bull boss Christian Horner says the team's straightline deficit at the Russian Grand Prix was "skewed" by Honda's power unit running out of battery deployment on the long straights.
The nature of the Sochi circuit, with very few heavy braking zones and long flat out sections, make it hard for the turbo hybrid engines to recover enough power throughout each lap to run at maximum boost for the entire length of the circuit.
That results in what is known as 'clipping' - when the power unit runs out of the extra 160hp battery boost towards the end of the straights.
With Red Bull having sent a radio message to Max Verstappen that he was losing six-tenths of a second on the straights to race leader Valtteri Bottas, it was clear where Mercedes had its advantage.
But Horner says that the performance in Russia was not representative of how the Honda stacks up at other venues where energy recovery is easier.
"I think this circuit was always going to be difficult for us," explained Horner. "We had quite a lot of clipping here and I think that has an effect.
"So I think it was sort of skewed by that energy recovery. But we knew that before we got here. So it was always going to be a more challenging race for us."
Horner was in no doubt Mercedes had the quicker car in Russia, so Verstappen's runner-up position was probably better than the team could realistically have hoped for anyway.
"I think Mercedes had a faster car than us this weekend," he said.
"Obviously we've benefited from Lewis's penalty, but I think, Max has just extracted every ounce of performance out of the car throughout the weekend. It's our best result here in the six years that we've been coming."
Asked if he felt Verstappen was actually outperforming the car at the moment, Horner replied: "Well, a car will only go as fast as somebody can drive it.
"We know that Max is driving at a very high level: we know that Lewis is capable of doing the same. Max, his qualifying lap in particular was sensational, and in the race he made no mistakes at all. It was a very mature and measured performance."