SPA-FRANCORCHAMPS, BELGIUM (AFP) - Team chief Toto Wolff on Saturday (Aug 27) slammed as "unacceptable" the qualifying performance of defending constructors' champions Mercedes at the Belgian Grand Prix, saying it was the worst he had known.
Wolff said he could not understand how they could be on pole at one race weekend and then 1.8 seconds off the pace at the following race three weeks later.
"You can't be on pole three weeks before - albeit for very different conditions, different track - and then be 1.8 seconds off the pace, at the next one," Wolff told reporters.
"There's something which we totally don't understand, or seem to get right. Clearly, Red Bull is here in a league of their own.
"What is the next Ferrari - eight or nine tenths off? So, I don't know what that is, but that is no consolation.
"For me, it's the worst qualifying session that I have had in 10 years. Irrespective of what positions we are going to start tomorrow, just even being on pole at one weekend and then three weeks later being nowhere is just not acceptable for ourselves."
Seven-time champion Lewis Hamilton and George Russell qualified seventh and eighth but will start from fourth and fifth due to grid penalties handed out to rivals for taking new engines for Sunday's race.
Russell was on pole at the last race in Hungary before Formula One's "summer break" where Hamilton finished second and he was third, their first double podium this year.
"If we could understand it, we could tune it," Wolff added.
"But the car is draggy in a straight line - Lewis said it's like a dragging a parachute behind him.
"And it is unstable on the rear. It under-steers, it bounces through the high speed and it gives no confidence. There is not one positive that I heard about how the car performs here this weekend and throughout the weekend.
"So, I think now it's time to consolidate and decide what we do next."
Russell said Mercedes' chief problem was in warming their tyres in cool conditions, a problem they have suffered throughout this season.
"They are the overriding factor," he said. "If you get the tyres in the right window, or the wrong window, it could be a second a lap difference... I think it is an inherent limitation in the car."
After reeling off eight consecutive constructors' championship triumphs, the team has struggled with this season's new "ground effect" formula and had problems with "porpoising" and bouncing, but showed signs of recovery in recent months.
But any hopes of a first win of the season look a long way off judging by Saturday's limp showing.