Seven-times world champion Lewis Hamilton finished 13th in qualifying on Saturday at the Miami Grand Prix and George Russell narrowly made it into sixth place on the grid as Mercedes again failed to keep pace with the dominant Red Bull.
Both Mercedes drivers struggled with their car in the tricky conditions on the resurfaced Miami track.
Red Bull's Sergio Perez has pole position heading into Sunday's race and adding to Mercedes woe, Fernando Alonso, in the Aston Martin, with a Mercedes engine, finished second-fastest.
Wolff was certainly in no mood to consider Russell's grid position any kind of positive.
"I take no enjoyment from finishing sixth. It's the lack of comprehension of what it is, that makes this car such a nasty piece of work," he said.
"The car is not a nice car, not a good car," said Wolff.
"I would say the performance is just really bad, and for George and Lewis it just really went south. You could see in the first sector the car really wasn't there.
"When things go bad they compound bad and this has happened for him (Hamilton) and for all of us as a team," he said.
Last year the Mercedes struggled at Miami with bouncing but Wolff said he said he expected more improvement from the past year's work.
"It is worse than I thought, we have had 12 months since we were last in Miami and the car is just marginally better.
"Maybe it is not bouncing on the straight but that is the only thing that is better than last year. The car is not fast enough and we haven't got any comprehension why that is. It is just not acceptable," he said.
Hamilton said the car's troubles had made it hard for him to push for a front-row position.
"It was a difficult session. We're not that quick so we really needed perfect laps but it was difficult to get into a rhythm, at the beginning I had that issue with the car going slow in the last corner," Hamilton continued.
"The last run I was the last of the pack and trying to get the temperatures into the tyres. I was at the back of the queue and everyone slowed into the last corner and I lost all temperatures and couldn't do the lap," he said.
Russell said his sixth position was a "flattering result" and that while Sunday's race was the priority, the team needed to look further ahead.
"We'll focus on tomorrow, but we need to think about the bigger picture and how we're going to bring the fight to the guys at the top," he said.
