Following criticism from some fans about the lack of volume of the new turbo engines compared to last year's V8s, Vettel believes that F1 has lost some of its magic this season.
Having watched from trackside at the Australian Grand Prix following his early retirement, he reckons the current cars sound terrible.
"It is s**t," declared Vettel when asked what he thought about the noise of the V6 turbo engines.
"I was on the pitwall during the race, and it is better [quieter] than in a bar!
"I think for the fans it is not good.
"I think F1 has to be spectacular - and the sound is one of the most important things.
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"I remember when, although I don't remember much because I was six years old, but we went to see the cars live in free practice in Germany, and the one thing I remember was the sound.
"[I remember] how loud the cars were, and to feel the cars through the ground as it was vibrating. It is a shame we don't have that anymore."
Vettel's remarks are aligned with those of F1 supremo Bernie Ecclestone, who has long been against the new engine rules.
The German's Red Bull team-mate Daniel Ricciardo acknowledged that the sound was quieter, but was more sanguine about the change.
"Once you're at full speed you still don't hear what's going on," said Ricciardo.
"There's still enough noise inside our helmets to block out the rest.
"I think it's alright. It's different, something else to get used to.
"I'll probably have good hearing for a bit longer so I'm not really complaining."
Lewis Hamilton, whose Mercedes is dominant at the moment, accepted that the noise was not as good - but believed that the new engines were better in other ways.
"It's OK," he said. "It's not special like it used to be, but it's a lot of power, so it's special in other ways."